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 A211516 #7 Nov 28 2021 13:40:55
%S A211516 0,0,1,3,3,5,7,9,12,14,16,18,20,24,28,32,34,36,39,43,47,51,55,59,63,
%T A211516 67,71,75,79,83,87,91,96,102,108,114,118,122,126,130,134,140,146,152,
%U A211516 158,164,170,176,182,186,191,197,203,209,215,221,227,233,239,245
%N A211516 Number of ordered triples (w,x,y) with all terms in {1,...,n} and w^2=x+y.
%C A211516 For a guide to related sequences, see A211422.
%F A211516 Conjecture: a(n) = -(2*n + 5/3)*w(n) + w(n)^2 + (2/3)*w(n)^3 + (2*n + 5/6)*w(2*n) - (1/2)*w(2*n)^2 - (1/3)*w(2*n)^3, where w = A000196. - _Velin Yanev_, Nov 16 2021
%t A211516 t[n_] := t[n] = Flatten[Table[w^2 - x - y, {w, 1, n}, {x, 1, n}, {y, 1, n}]]
%t A211516 c[n_] := Count[t[n], 0]
%t A211516 t = Table[c[n], {n, 0, 70}] (* A211516 *)
%Y A211516 Cf. A211422.
%K A211516 nonn
%O A211516 0,4
%A A211516 _Clark Kimberling_, Apr 14 2012