large numbers as counterexamples [duplicate]












1















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  • Conjectures that have been disproved with extremely large counterexamples?

    15 answers




Some mathematical patterns stay true for a set of integers $1..n$ only to break at $n+1$.



What are some nontrivial examples where $n$ is ``large''?



As an example $x^2+x+41$ is prime for $x=1..40$, but not at $41$.



I am particularly looking for examples other than prime producing polynomials. Especially examples suitable for an introductory class.










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marked as duplicate by Travis, Matthew Towers, Robert Israel number-theory
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Nov 26 at 14:26


This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.















  • $$binom nr>0$$ for $0le rle n$
    – lab bhattacharjee
    Nov 26 at 14:20










  • math.stackexchange.com/a/111461/76284
    – user76284
    Nov 26 at 14:20










  • In any case, a standard example is Skewes' Number: mathworld.wolfram.com/SkewesNumber.html
    – Travis
    Nov 26 at 14:22
















1















This question already has an answer here:




  • Conjectures that have been disproved with extremely large counterexamples?

    15 answers




Some mathematical patterns stay true for a set of integers $1..n$ only to break at $n+1$.



What are some nontrivial examples where $n$ is ``large''?



As an example $x^2+x+41$ is prime for $x=1..40$, but not at $41$.



I am particularly looking for examples other than prime producing polynomials. Especially examples suitable for an introductory class.










share|cite|improve this question













marked as duplicate by Travis, Matthew Towers, Robert Israel number-theory
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Nov 26 at 14:26


This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.















  • $$binom nr>0$$ for $0le rle n$
    – lab bhattacharjee
    Nov 26 at 14:20










  • math.stackexchange.com/a/111461/76284
    – user76284
    Nov 26 at 14:20










  • In any case, a standard example is Skewes' Number: mathworld.wolfram.com/SkewesNumber.html
    – Travis
    Nov 26 at 14:22














1












1








1


1






This question already has an answer here:




  • Conjectures that have been disproved with extremely large counterexamples?

    15 answers




Some mathematical patterns stay true for a set of integers $1..n$ only to break at $n+1$.



What are some nontrivial examples where $n$ is ``large''?



As an example $x^2+x+41$ is prime for $x=1..40$, but not at $41$.



I am particularly looking for examples other than prime producing polynomials. Especially examples suitable for an introductory class.










share|cite|improve this question














This question already has an answer here:




  • Conjectures that have been disproved with extremely large counterexamples?

    15 answers




Some mathematical patterns stay true for a set of integers $1..n$ only to break at $n+1$.



What are some nontrivial examples where $n$ is ``large''?



As an example $x^2+x+41$ is prime for $x=1..40$, but not at $41$.



I am particularly looking for examples other than prime producing polynomials. Especially examples suitable for an introductory class.





This question already has an answer here:




  • Conjectures that have been disproved with extremely large counterexamples?

    15 answers








geometry number-theory discrete-mathematics






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asked Nov 26 at 14:16









Maesumi

2,6881523




2,6881523




marked as duplicate by Travis, Matthew Towers, Robert Israel number-theory
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Nov 26 at 14:26


This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.






marked as duplicate by Travis, Matthew Towers, Robert Israel number-theory
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Nov 26 at 14:26


This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.














  • $$binom nr>0$$ for $0le rle n$
    – lab bhattacharjee
    Nov 26 at 14:20










  • math.stackexchange.com/a/111461/76284
    – user76284
    Nov 26 at 14:20










  • In any case, a standard example is Skewes' Number: mathworld.wolfram.com/SkewesNumber.html
    – Travis
    Nov 26 at 14:22


















  • $$binom nr>0$$ for $0le rle n$
    – lab bhattacharjee
    Nov 26 at 14:20










  • math.stackexchange.com/a/111461/76284
    – user76284
    Nov 26 at 14:20










  • In any case, a standard example is Skewes' Number: mathworld.wolfram.com/SkewesNumber.html
    – Travis
    Nov 26 at 14:22
















$$binom nr>0$$ for $0le rle n$
– lab bhattacharjee
Nov 26 at 14:20




$$binom nr>0$$ for $0le rle n$
– lab bhattacharjee
Nov 26 at 14:20












math.stackexchange.com/a/111461/76284
– user76284
Nov 26 at 14:20




math.stackexchange.com/a/111461/76284
– user76284
Nov 26 at 14:20












In any case, a standard example is Skewes' Number: mathworld.wolfram.com/SkewesNumber.html
– Travis
Nov 26 at 14:22




In any case, a standard example is Skewes' Number: mathworld.wolfram.com/SkewesNumber.html
– Travis
Nov 26 at 14:22










1 Answer
1






active

oldest

votes


















5














It's not number theory, but I've always found the Borwein integrals to be fascinating.



https://en.wikipedia.org/wiki/Borwein_integral






share|cite|improve this answer




























    1 Answer
    1






    active

    oldest

    votes








    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    5














    It's not number theory, but I've always found the Borwein integrals to be fascinating.



    https://en.wikipedia.org/wiki/Borwein_integral






    share|cite|improve this answer


























      5














      It's not number theory, but I've always found the Borwein integrals to be fascinating.



      https://en.wikipedia.org/wiki/Borwein_integral






      share|cite|improve this answer
























        5












        5








        5






        It's not number theory, but I've always found the Borwein integrals to be fascinating.



        https://en.wikipedia.org/wiki/Borwein_integral






        share|cite|improve this answer












        It's not number theory, but I've always found the Borwein integrals to be fascinating.



        https://en.wikipedia.org/wiki/Borwein_integral







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Nov 26 at 14:20









        Olivier Moschetta

        2,7761411




        2,7761411















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