

A111931


Smallest prime p such that 1/2, 2/3, 3/4, ..., (m1)/m are nth power nonresidues modulo p for maximum possible m (=A000236(n)).


1




OFFSET

2,1


COMMENTS

A000236(n) is the maximum length of a run of consecutive residues modulo prime p, starting with 1, where no two adjacent elements belong to the same nth power residue class (in other words, there is no nth power residue modulo p in the sequence of ratios 1/2, 2/3, ..., (A000236(n)1)/A000236(n)). a(n) equals the smallest p admitting a run of maximum length A000236(n).


LINKS



EXAMPLE

a(2)=11 since A000236(2)=3 and 1/2=6, 2/3=8 are nonsquares modulo 11, and there is no smaller prime modulo which 1/2 and 2/3 are nonsquares.


CROSSREFS



KEYWORD

hard,nonn,more


AUTHOR



EXTENSIONS



STATUS

approved



