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 A196362 #8 Mar 30 2012 18:57:49 %S A196362 2,3,4,5,6,6,7,7,8,9,10,10,10,10,11,11,12,12,13,14,14,14,14,15,15,15, %T A196362 15,16,16,16,16,17,18,18,18,19,19,20,20,20,20,21,21,21,22,22,22,22,23, %U A196362 23,24,24,25,25,26,26,26,26,27,27,28,28,28,28,29,30,30,30,30,30 %N A196362 Positive integers a for which there is a (-5/2)-Pythagorean triple (a,b,c) satisfying a<=b. %C A196362 See A195770 for definitions of k-Pythagorean triple, primitive k-Pythagorean triple, and lists of related sequences. %t A196362 z8 = 900; z9 = 250; z7 = 200; %t A196362 pIntegerQ := IntegerQ[#1] && #1 > 0 &; %t A196362 k = -5/2; c[a_, b_] := Sqrt[a^2 + b^2 + k*a*b]; %t A196362 d[a_, b_] := If[pIntegerQ[c[a, b]], {a, b, c[a, b]}, 0] %t A196362 t[a_] := Table[d[a, b], {b, a, z8}] %t A196362 u[n_] := Delete[t[n], Position[t[n], 0]] %t A196362 Table[u[n], {n, 1, 15}] %t A196362 t = Table[u[n], {n, 1, z8}]; %t A196362 Flatten[Position[t, {}]] %t A196362 u = Flatten[Delete[t, Position[t, {}]]]; %t A196362 x[n_] := u[[3 n - 2]]; %t A196362 Table[x[n], {n, 1, z7}] (* A196362 *) %t A196362 y[n_] := u[[3 n - 1]]; %t A196362 Table[y[n], {n, 1, z7}] (* A196363 *) %t A196362 z[n_] := u[[3 n]]; %t A196362 Table[z[n], {n, 1, z7}] (* A196364 *) %t A196362 x1[n_] := If[GCD[x[n], y[n], z[n]] == 1, x[n], 0] %t A196362 y1[n_] := If[GCD[x[n], y[n], z[n]] == 1, y[n], 0] %t A196362 z1[n_] := If[GCD[x[n], y[n], z[n]] == 1, z[n], 0] %t A196362 f = Table[x1[n], {n, 1, z9}]; %t A196362 x2 = Delete[f, Position[f, 0]] (* A196365 *) %t A196362 g = Table[y1[n], {n, 1, z9}]; %t A196362 y2 = Delete[g, Position[g, 0]] (* A196366 *) %t A196362 h = Table[z1[n], {n, 1, z9}]; %t A196362 z2 = Delete[h, Position[h, 0]] (* A196367 *) %Y A196362 Cf. A195770, A196363, A196364, A196365. %K A196362 nonn %O A196362 1,1 %A A196362 _Clark Kimberling_, Oct 01 2011