What is the remainder when $ n^n $ is divided by $ (n-1) $?












1












$begingroup$


I want to find out the remainder if $ n^n $ is divided by $(n-1)$ . I have tried investigating a number of examples for small $n$:





  • $ 2^2 $ is divided by $1$ gives remainder $0 $


  • $ 3^3 $ is divided by $2$ gives remainder $1$


  • $ 4^4 $ is divided by $3$ gives remainder $1$


  • $ 5^5 $ is divided by $4$ gives remainder $1$


  • $ 6^6 $ is divided by $5$ gives remainder $1$


But I can't identify any pattern to find out the remainder. So please help me to find out the remainder if $ n^n $ is divided by $ n-1 $.










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$endgroup$








  • 1




    $begingroup$
    $4^4$ divided by $3$ gives $1$. The answer is always $1$
    $endgroup$
    – Mohammad Zuhair Khan
    Dec 30 '18 at 9:58










  • $begingroup$
    That is a huge mistake . Many many thanks
    $endgroup$
    – Standard Equation
    Dec 30 '18 at 10:00


















1












$begingroup$


I want to find out the remainder if $ n^n $ is divided by $(n-1)$ . I have tried investigating a number of examples for small $n$:





  • $ 2^2 $ is divided by $1$ gives remainder $0 $


  • $ 3^3 $ is divided by $2$ gives remainder $1$


  • $ 4^4 $ is divided by $3$ gives remainder $1$


  • $ 5^5 $ is divided by $4$ gives remainder $1$


  • $ 6^6 $ is divided by $5$ gives remainder $1$


But I can't identify any pattern to find out the remainder. So please help me to find out the remainder if $ n^n $ is divided by $ n-1 $.










share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    $4^4$ divided by $3$ gives $1$. The answer is always $1$
    $endgroup$
    – Mohammad Zuhair Khan
    Dec 30 '18 at 9:58










  • $begingroup$
    That is a huge mistake . Many many thanks
    $endgroup$
    – Standard Equation
    Dec 30 '18 at 10:00
















1












1








1





$begingroup$


I want to find out the remainder if $ n^n $ is divided by $(n-1)$ . I have tried investigating a number of examples for small $n$:





  • $ 2^2 $ is divided by $1$ gives remainder $0 $


  • $ 3^3 $ is divided by $2$ gives remainder $1$


  • $ 4^4 $ is divided by $3$ gives remainder $1$


  • $ 5^5 $ is divided by $4$ gives remainder $1$


  • $ 6^6 $ is divided by $5$ gives remainder $1$


But I can't identify any pattern to find out the remainder. So please help me to find out the remainder if $ n^n $ is divided by $ n-1 $.










share|cite|improve this question











$endgroup$




I want to find out the remainder if $ n^n $ is divided by $(n-1)$ . I have tried investigating a number of examples for small $n$:





  • $ 2^2 $ is divided by $1$ gives remainder $0 $


  • $ 3^3 $ is divided by $2$ gives remainder $1$


  • $ 4^4 $ is divided by $3$ gives remainder $1$


  • $ 5^5 $ is divided by $4$ gives remainder $1$


  • $ 6^6 $ is divided by $5$ gives remainder $1$


But I can't identify any pattern to find out the remainder. So please help me to find out the remainder if $ n^n $ is divided by $ n-1 $.







elementary-number-theory






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edited Dec 30 '18 at 15:32









Bill Dubuque

214k29198660




214k29198660










asked Dec 30 '18 at 9:56









Standard EquationStandard Equation

247113




247113








  • 1




    $begingroup$
    $4^4$ divided by $3$ gives $1$. The answer is always $1$
    $endgroup$
    – Mohammad Zuhair Khan
    Dec 30 '18 at 9:58










  • $begingroup$
    That is a huge mistake . Many many thanks
    $endgroup$
    – Standard Equation
    Dec 30 '18 at 10:00
















  • 1




    $begingroup$
    $4^4$ divided by $3$ gives $1$. The answer is always $1$
    $endgroup$
    – Mohammad Zuhair Khan
    Dec 30 '18 at 9:58










  • $begingroup$
    That is a huge mistake . Many many thanks
    $endgroup$
    – Standard Equation
    Dec 30 '18 at 10:00










1




1




$begingroup$
$4^4$ divided by $3$ gives $1$. The answer is always $1$
$endgroup$
– Mohammad Zuhair Khan
Dec 30 '18 at 9:58




$begingroup$
$4^4$ divided by $3$ gives $1$. The answer is always $1$
$endgroup$
– Mohammad Zuhair Khan
Dec 30 '18 at 9:58












$begingroup$
That is a huge mistake . Many many thanks
$endgroup$
– Standard Equation
Dec 30 '18 at 10:00






$begingroup$
That is a huge mistake . Many many thanks
$endgroup$
– Standard Equation
Dec 30 '18 at 10:00












4 Answers
4






active

oldest

votes


















5












$begingroup$

The other answers are all correct. But since you posted such an elementary problem, I guess it would be better if you learnt how to attack this problem rather than only the solution of it.



See, you need to find out $n^n pmod{n-1}$ where $n>2$. Whenever you need to find mod of such products, the first thing to try is finding out the mod of individual terms (the others being some manipulation or Euler's/Fermat's little theorem if it's a power etc.). Now, in this case, it is evident that $n equiv (n-1)+1 equiv 1 pmod{n-1}$.



We know that, taking mod is multiplicative. So, $n^n equiv (1)^n pmod{n-1} equiv 1 pmod{n-1}$.



Please comment if you need further clarifications.






share|cite|improve this answer











$endgroup$









  • 1




    $begingroup$
    I think it would have better if you used equiv $equiv$ instead of =
    $endgroup$
    – Mohammad Zuhair Khan
    Dec 30 '18 at 11:12










  • $begingroup$
    @MohammadZuhairKhan You're right. Edited.
    $endgroup$
    – SinTan1729
    Dec 30 '18 at 15:24



















7












$begingroup$

$$n^n equiv ((n-1)+1)^n equiv 1^n equiv 1 pmod {n-1}$$






share|cite|improve this answer









$endgroup$













  • $begingroup$
    It would probably more helpful to the OP if you edited in where this equation comes from. (I understand it, but OP need not necessarily do so, it's mostly just an equation completely out of context. >_>)
    $endgroup$
    – Eevee Trainer
    Dec 30 '18 at 10:01






  • 1




    $begingroup$
    I cant understand your solution . Can you please make elaboration of this solution ?
    $endgroup$
    – Standard Equation
    Dec 30 '18 at 10:04










  • $begingroup$
    @StandardEquation Do you know modular arithmetic / congruences? It helps to add such context to your questions. You accepted an answer using modular arithmetic, so how could you understand that but not this? (they are equivalent)
    $endgroup$
    – Bill Dubuque
    Dec 30 '18 at 15:43





















7












$begingroup$

$n^n = (n^{n-1} + n^{n-2} +ldots + 1)(n-1) + 1$. Its a telescope sum.






share|cite|improve this answer











$endgroup$









  • 1




    $begingroup$
    It would probably more helpful to the OP if you edited in where this equation comes from. (I understand it, but OP need not necessarily do so, it's mostly just an equation completely out of context. >_>)
    $endgroup$
    – Eevee Trainer
    Dec 30 '18 at 10:01






  • 1




    $begingroup$
    This solution make sense to me . Many many thanks
    $endgroup$
    – Standard Equation
    Dec 30 '18 at 10:05



















4












$begingroup$

For n>2:



Binomial expansion:



$(1+(n-1))^n=$



$sum_{k=1}^{n}binom{n}{k}(n-1)^k+1;$



The first term is divisible by $(n-1)$, the remainder is $1$.






share|cite|improve this answer











$endgroup$













  • $begingroup$
    Except when $,|n-1| = 1,$ when the remainder $,r= 0neq 1,,$ but $,0equiv 1pmod{!pm!1},,$ i.e. $, requiv 1pmod{n!-!1} $ is always true.
    $endgroup$
    – Bill Dubuque
    Dec 30 '18 at 15:37












  • $begingroup$
    Bill.Oops. Thanks for your comment. n>2. Shall fix it.
    $endgroup$
    – Peter Szilas
    Dec 30 '18 at 17:41












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4 Answers
4






active

oldest

votes








4 Answers
4






active

oldest

votes









active

oldest

votes






active

oldest

votes









5












$begingroup$

The other answers are all correct. But since you posted such an elementary problem, I guess it would be better if you learnt how to attack this problem rather than only the solution of it.



See, you need to find out $n^n pmod{n-1}$ where $n>2$. Whenever you need to find mod of such products, the first thing to try is finding out the mod of individual terms (the others being some manipulation or Euler's/Fermat's little theorem if it's a power etc.). Now, in this case, it is evident that $n equiv (n-1)+1 equiv 1 pmod{n-1}$.



We know that, taking mod is multiplicative. So, $n^n equiv (1)^n pmod{n-1} equiv 1 pmod{n-1}$.



Please comment if you need further clarifications.






share|cite|improve this answer











$endgroup$









  • 1




    $begingroup$
    I think it would have better if you used equiv $equiv$ instead of =
    $endgroup$
    – Mohammad Zuhair Khan
    Dec 30 '18 at 11:12










  • $begingroup$
    @MohammadZuhairKhan You're right. Edited.
    $endgroup$
    – SinTan1729
    Dec 30 '18 at 15:24
















5












$begingroup$

The other answers are all correct. But since you posted such an elementary problem, I guess it would be better if you learnt how to attack this problem rather than only the solution of it.



See, you need to find out $n^n pmod{n-1}$ where $n>2$. Whenever you need to find mod of such products, the first thing to try is finding out the mod of individual terms (the others being some manipulation or Euler's/Fermat's little theorem if it's a power etc.). Now, in this case, it is evident that $n equiv (n-1)+1 equiv 1 pmod{n-1}$.



We know that, taking mod is multiplicative. So, $n^n equiv (1)^n pmod{n-1} equiv 1 pmod{n-1}$.



Please comment if you need further clarifications.






share|cite|improve this answer











$endgroup$









  • 1




    $begingroup$
    I think it would have better if you used equiv $equiv$ instead of =
    $endgroup$
    – Mohammad Zuhair Khan
    Dec 30 '18 at 11:12










  • $begingroup$
    @MohammadZuhairKhan You're right. Edited.
    $endgroup$
    – SinTan1729
    Dec 30 '18 at 15:24














5












5








5





$begingroup$

The other answers are all correct. But since you posted such an elementary problem, I guess it would be better if you learnt how to attack this problem rather than only the solution of it.



See, you need to find out $n^n pmod{n-1}$ where $n>2$. Whenever you need to find mod of such products, the first thing to try is finding out the mod of individual terms (the others being some manipulation or Euler's/Fermat's little theorem if it's a power etc.). Now, in this case, it is evident that $n equiv (n-1)+1 equiv 1 pmod{n-1}$.



We know that, taking mod is multiplicative. So, $n^n equiv (1)^n pmod{n-1} equiv 1 pmod{n-1}$.



Please comment if you need further clarifications.






share|cite|improve this answer











$endgroup$



The other answers are all correct. But since you posted such an elementary problem, I guess it would be better if you learnt how to attack this problem rather than only the solution of it.



See, you need to find out $n^n pmod{n-1}$ where $n>2$. Whenever you need to find mod of such products, the first thing to try is finding out the mod of individual terms (the others being some manipulation or Euler's/Fermat's little theorem if it's a power etc.). Now, in this case, it is evident that $n equiv (n-1)+1 equiv 1 pmod{n-1}$.



We know that, taking mod is multiplicative. So, $n^n equiv (1)^n pmod{n-1} equiv 1 pmod{n-1}$.



Please comment if you need further clarifications.







share|cite|improve this answer














share|cite|improve this answer



share|cite|improve this answer








edited Dec 30 '18 at 15:24

























answered Dec 30 '18 at 10:10









SinTan1729SinTan1729

2,689724




2,689724








  • 1




    $begingroup$
    I think it would have better if you used equiv $equiv$ instead of =
    $endgroup$
    – Mohammad Zuhair Khan
    Dec 30 '18 at 11:12










  • $begingroup$
    @MohammadZuhairKhan You're right. Edited.
    $endgroup$
    – SinTan1729
    Dec 30 '18 at 15:24














  • 1




    $begingroup$
    I think it would have better if you used equiv $equiv$ instead of =
    $endgroup$
    – Mohammad Zuhair Khan
    Dec 30 '18 at 11:12










  • $begingroup$
    @MohammadZuhairKhan You're right. Edited.
    $endgroup$
    – SinTan1729
    Dec 30 '18 at 15:24








1




1




$begingroup$
I think it would have better if you used equiv $equiv$ instead of =
$endgroup$
– Mohammad Zuhair Khan
Dec 30 '18 at 11:12




$begingroup$
I think it would have better if you used equiv $equiv$ instead of =
$endgroup$
– Mohammad Zuhair Khan
Dec 30 '18 at 11:12












$begingroup$
@MohammadZuhairKhan You're right. Edited.
$endgroup$
– SinTan1729
Dec 30 '18 at 15:24




$begingroup$
@MohammadZuhairKhan You're right. Edited.
$endgroup$
– SinTan1729
Dec 30 '18 at 15:24











7












$begingroup$

$$n^n equiv ((n-1)+1)^n equiv 1^n equiv 1 pmod {n-1}$$






share|cite|improve this answer









$endgroup$













  • $begingroup$
    It would probably more helpful to the OP if you edited in where this equation comes from. (I understand it, but OP need not necessarily do so, it's mostly just an equation completely out of context. >_>)
    $endgroup$
    – Eevee Trainer
    Dec 30 '18 at 10:01






  • 1




    $begingroup$
    I cant understand your solution . Can you please make elaboration of this solution ?
    $endgroup$
    – Standard Equation
    Dec 30 '18 at 10:04










  • $begingroup$
    @StandardEquation Do you know modular arithmetic / congruences? It helps to add such context to your questions. You accepted an answer using modular arithmetic, so how could you understand that but not this? (they are equivalent)
    $endgroup$
    – Bill Dubuque
    Dec 30 '18 at 15:43


















7












$begingroup$

$$n^n equiv ((n-1)+1)^n equiv 1^n equiv 1 pmod {n-1}$$






share|cite|improve this answer









$endgroup$













  • $begingroup$
    It would probably more helpful to the OP if you edited in where this equation comes from. (I understand it, but OP need not necessarily do so, it's mostly just an equation completely out of context. >_>)
    $endgroup$
    – Eevee Trainer
    Dec 30 '18 at 10:01






  • 1




    $begingroup$
    I cant understand your solution . Can you please make elaboration of this solution ?
    $endgroup$
    – Standard Equation
    Dec 30 '18 at 10:04










  • $begingroup$
    @StandardEquation Do you know modular arithmetic / congruences? It helps to add such context to your questions. You accepted an answer using modular arithmetic, so how could you understand that but not this? (they are equivalent)
    $endgroup$
    – Bill Dubuque
    Dec 30 '18 at 15:43
















7












7








7





$begingroup$

$$n^n equiv ((n-1)+1)^n equiv 1^n equiv 1 pmod {n-1}$$






share|cite|improve this answer









$endgroup$



$$n^n equiv ((n-1)+1)^n equiv 1^n equiv 1 pmod {n-1}$$







share|cite|improve this answer












share|cite|improve this answer



share|cite|improve this answer










answered Dec 30 '18 at 9:58









Kenny LauKenny Lau

20.1k2260




20.1k2260












  • $begingroup$
    It would probably more helpful to the OP if you edited in where this equation comes from. (I understand it, but OP need not necessarily do so, it's mostly just an equation completely out of context. >_>)
    $endgroup$
    – Eevee Trainer
    Dec 30 '18 at 10:01






  • 1




    $begingroup$
    I cant understand your solution . Can you please make elaboration of this solution ?
    $endgroup$
    – Standard Equation
    Dec 30 '18 at 10:04










  • $begingroup$
    @StandardEquation Do you know modular arithmetic / congruences? It helps to add such context to your questions. You accepted an answer using modular arithmetic, so how could you understand that but not this? (they are equivalent)
    $endgroup$
    – Bill Dubuque
    Dec 30 '18 at 15:43




















  • $begingroup$
    It would probably more helpful to the OP if you edited in where this equation comes from. (I understand it, but OP need not necessarily do so, it's mostly just an equation completely out of context. >_>)
    $endgroup$
    – Eevee Trainer
    Dec 30 '18 at 10:01






  • 1




    $begingroup$
    I cant understand your solution . Can you please make elaboration of this solution ?
    $endgroup$
    – Standard Equation
    Dec 30 '18 at 10:04










  • $begingroup$
    @StandardEquation Do you know modular arithmetic / congruences? It helps to add such context to your questions. You accepted an answer using modular arithmetic, so how could you understand that but not this? (they are equivalent)
    $endgroup$
    – Bill Dubuque
    Dec 30 '18 at 15:43


















$begingroup$
It would probably more helpful to the OP if you edited in where this equation comes from. (I understand it, but OP need not necessarily do so, it's mostly just an equation completely out of context. >_>)
$endgroup$
– Eevee Trainer
Dec 30 '18 at 10:01




$begingroup$
It would probably more helpful to the OP if you edited in where this equation comes from. (I understand it, but OP need not necessarily do so, it's mostly just an equation completely out of context. >_>)
$endgroup$
– Eevee Trainer
Dec 30 '18 at 10:01




1




1




$begingroup$
I cant understand your solution . Can you please make elaboration of this solution ?
$endgroup$
– Standard Equation
Dec 30 '18 at 10:04




$begingroup$
I cant understand your solution . Can you please make elaboration of this solution ?
$endgroup$
– Standard Equation
Dec 30 '18 at 10:04












$begingroup$
@StandardEquation Do you know modular arithmetic / congruences? It helps to add such context to your questions. You accepted an answer using modular arithmetic, so how could you understand that but not this? (they are equivalent)
$endgroup$
– Bill Dubuque
Dec 30 '18 at 15:43






$begingroup$
@StandardEquation Do you know modular arithmetic / congruences? It helps to add such context to your questions. You accepted an answer using modular arithmetic, so how could you understand that but not this? (they are equivalent)
$endgroup$
– Bill Dubuque
Dec 30 '18 at 15:43













7












$begingroup$

$n^n = (n^{n-1} + n^{n-2} +ldots + 1)(n-1) + 1$. Its a telescope sum.






share|cite|improve this answer











$endgroup$









  • 1




    $begingroup$
    It would probably more helpful to the OP if you edited in where this equation comes from. (I understand it, but OP need not necessarily do so, it's mostly just an equation completely out of context. >_>)
    $endgroup$
    – Eevee Trainer
    Dec 30 '18 at 10:01






  • 1




    $begingroup$
    This solution make sense to me . Many many thanks
    $endgroup$
    – Standard Equation
    Dec 30 '18 at 10:05
















7












$begingroup$

$n^n = (n^{n-1} + n^{n-2} +ldots + 1)(n-1) + 1$. Its a telescope sum.






share|cite|improve this answer











$endgroup$









  • 1




    $begingroup$
    It would probably more helpful to the OP if you edited in where this equation comes from. (I understand it, but OP need not necessarily do so, it's mostly just an equation completely out of context. >_>)
    $endgroup$
    – Eevee Trainer
    Dec 30 '18 at 10:01






  • 1




    $begingroup$
    This solution make sense to me . Many many thanks
    $endgroup$
    – Standard Equation
    Dec 30 '18 at 10:05














7












7








7





$begingroup$

$n^n = (n^{n-1} + n^{n-2} +ldots + 1)(n-1) + 1$. Its a telescope sum.






share|cite|improve this answer











$endgroup$



$n^n = (n^{n-1} + n^{n-2} +ldots + 1)(n-1) + 1$. Its a telescope sum.







share|cite|improve this answer














share|cite|improve this answer



share|cite|improve this answer








edited Dec 30 '18 at 17:23

























answered Dec 30 '18 at 10:00









WuestenfuxWuestenfux

5,5911513




5,5911513








  • 1




    $begingroup$
    It would probably more helpful to the OP if you edited in where this equation comes from. (I understand it, but OP need not necessarily do so, it's mostly just an equation completely out of context. >_>)
    $endgroup$
    – Eevee Trainer
    Dec 30 '18 at 10:01






  • 1




    $begingroup$
    This solution make sense to me . Many many thanks
    $endgroup$
    – Standard Equation
    Dec 30 '18 at 10:05














  • 1




    $begingroup$
    It would probably more helpful to the OP if you edited in where this equation comes from. (I understand it, but OP need not necessarily do so, it's mostly just an equation completely out of context. >_>)
    $endgroup$
    – Eevee Trainer
    Dec 30 '18 at 10:01






  • 1




    $begingroup$
    This solution make sense to me . Many many thanks
    $endgroup$
    – Standard Equation
    Dec 30 '18 at 10:05








1




1




$begingroup$
It would probably more helpful to the OP if you edited in where this equation comes from. (I understand it, but OP need not necessarily do so, it's mostly just an equation completely out of context. >_>)
$endgroup$
– Eevee Trainer
Dec 30 '18 at 10:01




$begingroup$
It would probably more helpful to the OP if you edited in where this equation comes from. (I understand it, but OP need not necessarily do so, it's mostly just an equation completely out of context. >_>)
$endgroup$
– Eevee Trainer
Dec 30 '18 at 10:01




1




1




$begingroup$
This solution make sense to me . Many many thanks
$endgroup$
– Standard Equation
Dec 30 '18 at 10:05




$begingroup$
This solution make sense to me . Many many thanks
$endgroup$
– Standard Equation
Dec 30 '18 at 10:05











4












$begingroup$

For n>2:



Binomial expansion:



$(1+(n-1))^n=$



$sum_{k=1}^{n}binom{n}{k}(n-1)^k+1;$



The first term is divisible by $(n-1)$, the remainder is $1$.






share|cite|improve this answer











$endgroup$













  • $begingroup$
    Except when $,|n-1| = 1,$ when the remainder $,r= 0neq 1,,$ but $,0equiv 1pmod{!pm!1},,$ i.e. $, requiv 1pmod{n!-!1} $ is always true.
    $endgroup$
    – Bill Dubuque
    Dec 30 '18 at 15:37












  • $begingroup$
    Bill.Oops. Thanks for your comment. n>2. Shall fix it.
    $endgroup$
    – Peter Szilas
    Dec 30 '18 at 17:41
















4












$begingroup$

For n>2:



Binomial expansion:



$(1+(n-1))^n=$



$sum_{k=1}^{n}binom{n}{k}(n-1)^k+1;$



The first term is divisible by $(n-1)$, the remainder is $1$.






share|cite|improve this answer











$endgroup$













  • $begingroup$
    Except when $,|n-1| = 1,$ when the remainder $,r= 0neq 1,,$ but $,0equiv 1pmod{!pm!1},,$ i.e. $, requiv 1pmod{n!-!1} $ is always true.
    $endgroup$
    – Bill Dubuque
    Dec 30 '18 at 15:37












  • $begingroup$
    Bill.Oops. Thanks for your comment. n>2. Shall fix it.
    $endgroup$
    – Peter Szilas
    Dec 30 '18 at 17:41














4












4








4





$begingroup$

For n>2:



Binomial expansion:



$(1+(n-1))^n=$



$sum_{k=1}^{n}binom{n}{k}(n-1)^k+1;$



The first term is divisible by $(n-1)$, the remainder is $1$.






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$endgroup$



For n>2:



Binomial expansion:



$(1+(n-1))^n=$



$sum_{k=1}^{n}binom{n}{k}(n-1)^k+1;$



The first term is divisible by $(n-1)$, the remainder is $1$.







share|cite|improve this answer














share|cite|improve this answer



share|cite|improve this answer








edited Dec 30 '18 at 17:42

























answered Dec 30 '18 at 10:06









Peter SzilasPeter Szilas

12k2822




12k2822












  • $begingroup$
    Except when $,|n-1| = 1,$ when the remainder $,r= 0neq 1,,$ but $,0equiv 1pmod{!pm!1},,$ i.e. $, requiv 1pmod{n!-!1} $ is always true.
    $endgroup$
    – Bill Dubuque
    Dec 30 '18 at 15:37












  • $begingroup$
    Bill.Oops. Thanks for your comment. n>2. Shall fix it.
    $endgroup$
    – Peter Szilas
    Dec 30 '18 at 17:41


















  • $begingroup$
    Except when $,|n-1| = 1,$ when the remainder $,r= 0neq 1,,$ but $,0equiv 1pmod{!pm!1},,$ i.e. $, requiv 1pmod{n!-!1} $ is always true.
    $endgroup$
    – Bill Dubuque
    Dec 30 '18 at 15:37












  • $begingroup$
    Bill.Oops. Thanks for your comment. n>2. Shall fix it.
    $endgroup$
    – Peter Szilas
    Dec 30 '18 at 17:41
















$begingroup$
Except when $,|n-1| = 1,$ when the remainder $,r= 0neq 1,,$ but $,0equiv 1pmod{!pm!1},,$ i.e. $, requiv 1pmod{n!-!1} $ is always true.
$endgroup$
– Bill Dubuque
Dec 30 '18 at 15:37






$begingroup$
Except when $,|n-1| = 1,$ when the remainder $,r= 0neq 1,,$ but $,0equiv 1pmod{!pm!1},,$ i.e. $, requiv 1pmod{n!-!1} $ is always true.
$endgroup$
– Bill Dubuque
Dec 30 '18 at 15:37














$begingroup$
Bill.Oops. Thanks for your comment. n>2. Shall fix it.
$endgroup$
– Peter Szilas
Dec 30 '18 at 17:41




$begingroup$
Bill.Oops. Thanks for your comment. n>2. Shall fix it.
$endgroup$
– Peter Szilas
Dec 30 '18 at 17:41


















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