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).

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

1,1

Comments

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

Links

N. J. A. Sloane, Table of n, a(n) for n = 1..48

Formula

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

Crossrefs

Cf. A216955, A217942.

Sequence in context: A035592 A327050 A301554 * A346679 A232434 A096238

Adjacent sequences: A217938 A217939 A217940 * A217942 A217943 A217944

Keyword

nonn

Author

N. J. A. Sloane, Oct 23 2012

Status

approved