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 A248149 #4 Oct 02 2014 22:36:49 %S A248149 6,12,17,22,27,32,37,42,47,52,57,62,67,72,77,82,87,92,97,102,107,112, %T A248149 116,121,126,131,136,141,146,151,155,160,165,170,175,180,185,190,194, %U A248149 199,204,209,214,219,224,228,233,238,243,248,253,258,262,267,272,277 %N A248149 Numbers k such that A248148(k+1) = A248148(k). %H A248149 Clark Kimberling, <a href="/A248149/b248149.txt">Table of n, a(n) for n = 1..400</a> %t A248149 z = 400; p[k_] := p[k] = Sum[1/Binomial[2 h, h], {h, 1, k}] ; r = 1/3 + 2 Pi/Sqrt[243]; %t A248149 N[Table[r - p[n], {n, 1, z/50}]] %t A248149 f[n_] := f[n] = Select[Range[z], r - p[#] < 1/3^n &, 1] %t A248149 u = Flatten[Table[f[n], {n, 1, z}]] (* A248148 *) %t A248149 v = Flatten[Position[Differences[u], 0]] (* A248149 *) %Y A248149 Cf. A248148, A248111. %K A248149 nonn,easy %O A248149 1,1 %A A248149 _Clark Kimberling_, Oct 02 2014