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 A194104 #5 Mar 30 2012 18:57:40 %S A194104 1,3,2,7,4,5,12,8,9,6,19,13,14,10,11,27,20,21,15,16,17,36,28,29,22,23, %T A194104 24,18,47,37,38,30,31,32,25,26,59,48,49,39,40,41,33,34,35,73,60,61,50, %U A194104 51,52,42,43,44,45,88,74,75,62,63,64,53,54,55,56,46,104,89,90 %N A194104 Natural interspersion of A194102; a rectangular array, by antidiagonals. %C A194104 See A194029 for definitions of natural fractal sequence and natural interspersion. Every positive integer occurs exactly once (and every pair of rows intersperse), so that as a sequence, A194100 is a permutation of the positive integers; its inverse is A194101. %e A194104 Northwest corner: %e A194104 1...3...7...12...19 %e A194104 2...4...8...13...20 %e A194104 5...9...14..21...29 %e A194104 6...10..15..22...30 %e A194104 11..16..23..31...40 %t A194104 z = 40; g = Sqrt[2]; %t A194104 c[k_] := Sum[Floor[j*g], {j, 1, k}]; %t A194104 c = Table[c[k], {k, 1, z}] (* A194102 *) %t A194104 f[n_] := If[MemberQ[c, n], 1, 1 + f[n - 1]] %t A194104 f = Table[f[n], {n, 1, 800}] (* A194103 new *) %t A194104 r[n_] := Flatten[Position[f, n]] %t A194104 t[n_, k_] := r[n][[k]] %t A194104 TableForm[Table[t[n, k], {n, 1, 8}, {k, 1, 7}]] %t A194104 p = Flatten[Table[t[k, n - k + 1], {n, 1, 16}, {k, 1, n}]] (* A194104 *) %t A194104 q[n_] := Position[p, n]; Flatten[Table[q[n], {n, 1, 80}]] (* A194105 *) %Y A194104 Cf. A194029, A194102, A194103, A194105. %K A194104 nonn,tabl %O A194104 1,2 %A A194104 _Clark Kimberling_, Aug 15 2011