OFFSET
1,1
COMMENTS
n such that n is not divisible by 4, all primes dividing n are in A038873, and at least one prime dividing n is in A003630. - Robert Israel, Jul 19 2017
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Quadratic Nonresidue.
MAPLE
select(t -> numtheory:-quadres(2, t) = 1 and numtheory:-quadres(3, t)=-1, [$1..1000]); # Robert Israel, Jul 19 2017
MATHEMATICA
Select[Range[500], Min @ Complement[Range[# - 1], Mod[Range[#/2]^2, #]] == 3 &] (* Amiram Eldar, Oct 31 2020 *)
PROG
(PARI) residue(n, m)={local(r); r=0; for(i=1, floor(m/2), if(i^2%m==n, r=1)); r}
isA025021(n)=residue(2, n) && !residue(3, n) \\ Michael B. Porter, Apr 18 2010
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved