

A317724


Smallest prime q < A266829(n) such that both A266829(n)^(q1) == 1 (mod q^2) and q^(A266829(n)1) == 1 (mod A266829(n)^2), i.e., smallest prime q less than A266829(n) such that q and A266829(n) form a double Wieferich prime pair.


1




OFFSET

1,1


LINKS

Table of n, a(n) for n=1..6.
Eric Weisstein's World of Mathematics, Double Wieferich Prime Pair


EXAMPLE

a(2) = 83, because 83 is the smallest prime q such that A266829(2) = 4871 satisfies both 4871^(q1) == 1 (mod q^2) and q^(48711) == 1 (mod 4871^2).


PROG

(PARI) forprime(p=3, , forprime(q=2, p1, if(Mod(p, q^2)^(q1)==1 && Mod(q, p^2)^(p1)==1, print1(q, ", "); break)))


CROSSREFS

Cf. A266829. Supersequence of A124121.
Cf. A282293.
Sequence in context: A266201 A225807 A232770 * A099373 A169601 A205643
Adjacent sequences: A317721 A317722 A317723 * A317725 A317726 A317727


KEYWORD

nonn,hard,more


AUTHOR

Felix FrÃ¶hlich, Aug 05 2018


STATUS

approved



