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 A242655 #11 Jul 04 2014 11:44:45 %S A242655 0,2,3,7,8,12,15,18,27,28,32,35,42,43,47,48,50,58,60,63,72,75,82,83, %T A242655 87,90,98,103,107,108,112,115,122,123,128,135,138,140,147,162,163,167, %U A242655 168,172,175,183,188,192,200,202,203,207,210,218,223,232,235,240,242,243,252,258,263,267,282,283,287,288,290,298,300 %N A242655 Numbers of the form 2x^2+2xy+3y^2 with x and y nonnegative. %C A242655 Discriminant = -20. %H A242655 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) %Y A242655 For primes see A106864. Cf. A029718, A106865. %K A242655 nonn %O A242655 1,2 %A A242655 _N. J. A. Sloane_, May 30 2014