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 A244780 #7 Oct 31 2016 10:22:21
%S A244780 1,3,5,9,11,15,23,25,27,31,33,37,45,47,53,55,59,67,69,71,75,81,89,93,
%T A244780 97,99,103,111,113,115,125,135,137,141,155,157,159,163,165,177,179,
%U A244780 181,185,191,199,201,207,213,223,225,229,235,243,251,253,257,265,267
%N A244780 Positive numbers primitively represented by the binary quadratic form (1, 1, 3).
%C A244780 Discriminant = -11.
%H A244780 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)
%p A244780 # Function PriRepBQF in A244779.
%p A244780 A244780_list := n -> PriRepBQF(1, 1, 3, n); A244780_list(267);
%t A244780 Reap[For[n = 1, n < 1000, n++, r = Reduce[x^2 + x y + 3 y^2 == n, {x, y}, Integers]; If[r =!= False, If[AnyTrue[{x, y} /. {ToRules[r /. C[1] -> 0]}, CoprimeQ @@ # &], Sow[n]]]]][[2, 1]] (* _Jean-François Alcover_, Oct 31 2016 *)
%Y A244780 Cf. A244779, A244819.
%K A244780 nonn
%O A244780 1,2
%A A244780 _Peter Luschny_, Jul 06 2014