%I #22 Jul 30 2020 12:22:33
%S 1,2,4,5,8,9,10,16,18,20,23,25,31,32,36,37,40,41,43,45,46,49,50,59,61,
%T 62,64,72,73,74,80,81,82,83,86,90,92,98,100,103,107,113,115,118,121,
%U 122,124,125,127,128,131,139,144,146,148,155,160,162,163,164
%N Indices of nonzero terms in expansion of Dirichlet series Product_p (1-(Kronecker(m,p)+1)*p^(-s)+Kronecker(m,p)*p^(-2s))^(-1) for m= 41.
%C Also, positive numbers represented by 2x^2+3xy-4y^2, discriminant 41.
%H N. J. A. Sloane et al., <a href="https://oeis.org/wiki/Binary_Quadratic_Forms_and_OEIS">Binary Quadratic Forms and OEIS</a> (Index to related sequences, programs, references)
%t Reap[For[n = 0, n <= 100, n++, If[Reduce[ 2*x^2 + 3*x*y - 4*y^2 == n, {x, y}, Integers] =!= False, Sow[n]]]][[2, 1]] (* _N. J. A. Sloane_, Jun 05 2014 *)
%o (PARI) m=41; select(x -> x, direuler(p=2,101,1/(1-(kronecker(m,p)*(X-X^2))-X)), 1) \\ Fixed by _Andrey Zabolotskiy_, Jul 30 2020
%Y Primes: A141181.
%Y Cf. A035223.
%K nonn
%O 1,2
%A _N. J. A. Sloane_
%E More terms from _Colin Barker_, Jun 17 2014
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