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 A217941 #7 Oct 23 2012 15:36:05
%S A217941 2,6,14,32,66,140,282,574,1156,2326,4654,9348,18698,37436,74904,
%T A217941 149896,299794,599780,1199562,2399448,4798996,9598556,19197114,
%U A217941 38395584,76791200,153584626,307169622,614343808,1228687618,2457384892,4914769786,9829557516,19659116482,39318268388
%N A217941 a(n) = Sum_{k=1..n} k*C(n,k), where C(n,k) = number of binary sequences of length n and curling number k (A216955).
%C A217941 a(n)/2^n appears to be converging to 2.2886...
%H A217941 N. J. A. Sloane, <a href="/A217941/b217941.txt">Table of n, a(n) for n = 1..48</a>
%F A217941 For n>=1, a(2n+1) = 2*a(2n)+2, while a(2n) is a mystery.
%Y A217941 Cf. A216955, A217942.
%K A217941 nonn
%O A217941 1,1
%A A217941 _N. J. A. Sloane_, Oct 23 2012