A121999 Primes p such that p^2 divides Sierpinski number A014566((p-1)/2).

29, 37, 3373

Offset

1,1

Comments

Subsequence of A003628.

No other terms below 10^11. - Max Alekseyev, Sep 18 2010

Links

Table of n, a(n) for n=1..3.

Eric Weisstein's World of Mathematics, Sierpinski Number of the First Kind.

Formula

Elements of A125854 that are congruent to 5 or 7 modulo 8, i.e., primes p such that p == 5 or 7 (mod 8) and 2^(p-1) == 1+p (mod p^2). - Max Alekseyev, Sep 18 2010

Mathematica

Do[p=Prime[n]; f=((p-1)/2)^((p-1)/2)+1; If[IntegerQ[f/p^2], Print[p]], {n, 1, 3373}]

Prog

(PARI) { forprime(p=3, 10^11, if(Mod((p-1)/2, p^2)^((p-1)/2)==-1, print(p); )) } \\ Max Alekseyev, Sep 18 2010

Crossrefs

Cf. A014566, A003628.

Sequence in context: A152865 A333422 A108272 * A069530 A259032 A087144

Adjacent sequences: A121996 A121997 A121998 * A122000 A122001 A122002

Keyword

bref,more,nonn

Author

Alexander Adamchuk, Sep 11 2006

Status

approved