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 A020676 #18 Mar 15 2018 04:44:10
%S A020676 0,2,8,9,11,17,18,27,32,36,38,41,44,50,54,59,68,72,81,83,86,89,98,99,
%T A020676 107,108,113,128,131,134,137,144,146,152,153,162,164,171,176,179,194,
%U A020676 198,200,209,216,225,227,233,236,242,243,251,257,272,275,278,281,288,297,306,323
%N A020676 Numbers of form 2 x^2 + 9 y^2.
%H A020676 Harvey P. Dale, <a href="/A020676/b020676.txt">Table of n, a(n) for n = 1..1000</a>
%H A020676 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 A020676 With[{upto = 350}, Select[Union[2#[[1]]^2 + 9#[[2]]^2&/@Tuples[Range[0, Ceiling[Sqrt[upto^2/2]]], 2]], # <= upto &]] (* _Harvey P. Dale_, May 30 2017 *)
%Y A020676 Subsequences include A001105, A016766.
%Y A020676 Cf. A106949 (prime terms).
%K A020676 easy,nonn
%O A020676 1,2
%A A020676 _David W. Wilson_