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 A232639 #4 Nov 30 2013 14:08:19
%S A232639 1,2,3,4,5,7,6,9,8,12,11,17,10,15,14,22,13,20,19,30,18,28,27,43,16,25,
%T A232639 24,38,23,36,35,56,21,33,32,51,31,49,48,77,29,46,45,72,44,70,69,111,
%U A232639 26,41,40,64,39,62,61,98,37,59,58,93,57,91,90,145,34,54
%N A232639 Inverse permutation of the sequence of positive integers at A232638.
%H A232639 Clark Kimberling, <a href="/A232639/b232639.txt">Table of n, a(n) for n = 1..1000</a>
%t A232639 z = 14; g[1] = {1}; g[2] = {2}; g[n_] := Riffle[g[n - 1] + 1, 2 g[n - 1] - 1]; j[2] = Join[g[1], g[2]]; j[n_] := Join[j[n - 1], g[n]]; g1[n_] := DeleteDuplicates[DeleteCases[g[n], Alternatives @@ j[n - 1]]]; g1[1] = g[1]; g1[2] = g[2]; t = Flatten[Table[g1[n], {n, 1, z}]] (* A232638 *)
%t A232639 Table[Length[g1[n]], {n, 1, z}] (* A000045 *)
%t A232639 Flatten[Table[Position[t, n], {n, 1, 200}]] (* A232639 *)
%Y A232639 Cf. A232559, A232638, A000045.
%K A232639 nonn,easy
%O A232639 1,2
%A A232639 _Clark Kimberling_, Nov 28 2013