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 A211506 #4 Apr 19 2012 17:39:01
%S A211506 0,0,2,3,2,5,6,7,9,11,10,9,13,17,14,14,29,17,18,25,21,28,26,17,32,59,
%T A211506 24,28,39,37,28,41,36,42,50,28,91,55,26,44,66,55,40,57,59,67,70,31,65,
%U A211506 151,48,62,85,57,68,70,78,84,72,55,92,115,38,71,210,88,80,89
%N A211506 Number of ordered triples (w,x,y) with all terms in {1,...,n} and w^2=x*y+n.
%C A211506 For a guide to related sequences, see A211422.
%t A211506 t[n_] := t[n] = Flatten[Table[w^2 - x*y - n, {w, 1, n}, {x, 1, n}, {y, 1, n}]]
%t A211506 c[n_] := Count[t[n], 0]
%t A211506 t = Table[c[n], {n, 0, 80}] (* A211506 *)
%Y A211506 Cf. A211422.
%K A211506 nonn
%O A211506 0,3
%A A211506 _Clark Kimberling_, Apr 14 2012