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 A211509 #4 Apr 19 2012 17:39:29
%S A211509 0,1,0,2,3,4,4,4,8,7,6,10,10,8,16,10,11,16,14,8,22,12,18,24,18,13,26,
%T A211509 18,20,24,24,10,36,22,20,30,29,20,42,20,22,30,36,24,44,24,28,40,38,15,
%U A211509 48,26,34,48,38,18,50,38,42,38,44,18,66,42,35,50,38,32,68,24,36
%N A211509 Number of ordered triples (w,x,y) with all terms in {1,...,n} and w^2=2n-x*y.
%C A211509 For a guide to related sequences, see A211422.
%t A211509 t[n_] := t[n] = Flatten[Table[w^2 + x*y - 2 n, {w, 1, n}, {x, 1, n}, {y, 1, n}]]
%t A211509 c[n_] := Count[t[n], 0]
%t A211509 t = Table[c[n], {n, 0, 70}] (* A211509 *)
%Y A211509 Cf. A211422.
%K A211509 nonn
%O A211509 0,4
%A A211509 _Clark Kimberling_, Apr 14 2012