OFFSET
1,1
COMMENTS
Rational primes that decompose in the field Q(sqrt(6)). - N. J. A. Sloane, Dec 26 2017
All terms belong to A038876(n) = Primes p such that 6 is a square mod p. Only first two terms of A038876(n), 2 and 3, do not belong to a(n). - Alexander Adamchuk, May 04 2007
From Jianing Song, Oct 13 2022: (Start)
Primes p such that kronecker(6,p) = 1 (or equivalently, kronecker(24,p) = 1).
Primes congruent to 1, 5, 9, 23 modulo 24. (End)
LINKS
FORMULA
a(n) = A038876(n+1). - Alexander Adamchuk, May 04 2007
EXAMPLE
For p=5, 3^2 - 2^2 = 5.
MATHEMATICA
okQ[n_]:=Module[{c=(n-1)/2}, Divisible[3^c-2^c, n]]; Select[Prime[Range[200]], okQ] (* Harvey P. Dale, Apr 13 2011 *)
PROG
(PARI) /* Set x=3, d=1, s=-1 */
ptopm1d2(n, x, d, s) = { forprime(p=3, n, p2=(p-1)/2; y=x^p2 + s*(x-d)^p2; if(y%p==0, print1(p", "))) }
(PARI) isA097934(p) == isprime(p) && kronecker(6, p) == 1 \\ Jianing Song, Oct 13 2022
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Cino Hilliard, Sep 04 2004
STATUS
approved