OFFSET
1,1
COMMENTS
Primes that divide some member of A202018.
Primes congruent to x^2 mod 163 for some x, 0 <= x <= 162.
Primes of the form x^2 + xy + 41y^2. Also, primes of the form x^2 - xy + 41y^2 with x and y nonnegative. - Jianing Song, Feb 19 2021
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
FORMULA
a(n) ~ 2n log n. - Charles R Greathouse IV, Nov 28 2016
MAPLE
select(p -> isprime(p) and (p=163 or numtheory:-legendre(-163, p)=1), [seq(2*i+1, i=1..1000)]);
# Another Maple program is given in A296920. - N. J. A. Sloane, Dec 25 2017
MATHEMATICA
Reap[For[p=3, p<1000, p = NextPrime[p], If[p==163 || KroneckerSymbol[-163, p] == 1, Print[p]; Sow[p]]]][[2, 1]] (* Jean-François Alcover, Apr 29 2019 *)
PROG
(PARI) is(n)=isprime(n) && issquare(Mod(-163, n)) \\ Charles R Greathouse IV, Nov 28 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Robert Israel, Apr 20 2015
STATUS
approved