OFFSET
1,2
MATHEMATICA
Reap[For[n = 1, n < 200, n++, r = Reduce[x^2 + x y + 3 y^2 == n, {x, y}, Integers]; If[r =!= False, Sow[n]]]][[2, 1]] (* Jean-François Alcover, Oct 31 2016 *)
PROG
(PARI) m=-11; select(x -> x, direuler(p=2, 101, 1/(1-(kronecker(m, p)*(X-X^2))-X)), 1) \\ Fixed by Andrey Zabolotskiy, Jul 30 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from Jean-François Alcover, Oct 31 2016
Name corrected by Andrey Zabolotskiy, Jul 30 2020
STATUS
approved