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 A243190 #17 Jun 10 2020 08:57:30
%S A243190 0,3,7,12,22,27,28,30,43,48,55,63,67,70,75,88,102,103,108,112,118,120,
%T A243190 127,142,147,163,172,175,183,187,192,198,220,223,238,243,252,255,262,
%U A243190 268,270,280,283,295,300,307,318,327,343,352,355,358,363,367,382
%N A243190 Nonnegative numbers of the form -2x^2+6xy+3y^2.
%C A243190 Discriminant 60.
%C A243190 Also: nonnegative 3x^2-5y^2 since 3y^2+6xy-2x^2 = 3(y+x)^2-5x^2. - _R. J. Mathar_, Jun 10 2020
%H A243190 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 A243190 Reap[For[n = 0, n <= 200, n++, If[Reduce[-2*x^2 + 6*x*y + 3*y^2 == n, {x, y}, Integers] =!= False, Sow[n]]]][[2, 1]]
%Y A243190 Primes: A141304. Cf. A243188, A107152, A237606, A141302, A243189, A141303.
%K A243190 nonn
%O A243190 1,2
%A A243190 _N. J. A. Sloane_, Jun 05 2014
%E A243190 0 prepended and more terms from _Colin Barker_, Apr 07 2015