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 A212101 #6 Dec 04 2016 19:46:29
%S A212101 0,1,4,9,20,29,42,55,80,109,132,153,196,221,254,287,356,389,460,497,
%T A212101 568,617,670,715,808,897,960,1057,1156,1213,1306,1367,1512,1589,1672,
%U A212101 1749,1964,2037,2130,2223,2376,2457,2580,2665,2824,2997,3110
%N A212101 Number of (w,x,y,z) with all terms in {1,...,n} and w*x^2=y*z^2.
%C A212101 For a guide to related sequences, see A211795.
%e A212101 The four (w,x,y,z) counted by a(2): (1,1,1,1), (1,2,1,2), (2,1,2,1), (2,2,2,2).
%t A212101 t = Compile[{{n, _Integer}}, Module[{s = 0},
%t A212101 (Do[If[w*x^2 == y*z^2, s = s + 1],
%t A212101 {w, 1, #}, {x, 1, #}, {y, 1, #}, {z, 1, #}] &[n]; s)]];
%t A212101 Map[t[#] &, Range[0, 60]] (* A212101 *)
%t A212101 (* _Peter J. C. Moses_, Apr 13 2012 *)
%Y A212101 Cf. A211795.
%K A212101 nonn
%O A212101 0,3
%A A212101 _Clark Kimberling_, May 03 2012