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A121999 Primes p such that p^2 divides Sierpinski number A014566((p-1)/2). 6
29, 37, 3373 (list; graph; refs; listen; history; text; internal format)
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: A167470 A152865 A108272 * A069530 A259032 A087144

Adjacent sequences:  A121996 A121997 A121998 * A122000 A122001 A122002

KEYWORD

bref,more,nonn

AUTHOR

Alexander Adamchuk, Sep 11 2006

STATUS

approved

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Last modified November 21 05:14 EST 2018. Contains 317428 sequences. (Running on oeis4.)