cp's OEIS Frontend

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.

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).

Original entry on oeis.org

2, 6, 14, 32, 66, 140, 282, 574, 1156, 2326, 4654, 9348, 18698, 37436, 74904, 149896, 299794, 599780, 1199562, 2399448, 4798996, 9598556, 19197114, 38395584, 76791200, 153584626, 307169622, 614343808, 1228687618, 2457384892, 4914769786, 9829557516, 19659116482, 39318268388
Offset: 1

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Author

N. J. A. Sloane, Oct 23 2012

Keywords

Comments

a(n)/2^n appears to be converging to 2.2886...

Crossrefs

Formula

For n>=1, a(2n+1) = 2*a(2n)+2, while a(2n) is a mystery.