This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A035269 #22 Jul 30 2020 12:22:33
%S A035269 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 A035269 62,64,72,73,74,80,81,82,83,86,90,92,98,100,103,107,113,115,118,121,
%U A035269 122,124,125,127,128,131,139,144,146,148,155,160,162,163,164
%N A035269 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 A035269 Also, positive numbers represented by 2x^2+3xy-4y^2, discriminant 41.
%H A035269 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 A035269 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 A035269 (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 A035269 Primes: A141181.
%Y A035269 Cf. A035223.
%K A035269 nonn
%O A035269 1,2
%A A035269 _N. J. A. Sloane_
%E A035269 More terms from _Colin Barker_, Jun 17 2014