A211965 Number of binary sequences of length 2n-1 and curling number 1.

2, 4, 12, 40, 148, 572, 2248, 8920, 35536, 141860, 566880, 2266400, 9063372, 36249044, 144987304, 579931488, 2319690516, 9278691224, 37114623248, 148458209744, 593832272556, 2375327957436, 9501309564288, 38005233726372, 152020925844036

Offset

1,1

Comments

Equivalently, number of binary sequences of length 2n-1 with no initial repeats (see A122536).

Links

Table of n, a(n) for n=1..25.

B. Chaffin, J. P. Linderman, N. J. A. Sloane and Allan Wilks, On Curling Numbers of Integer Sequences, arXiv:1212.6102

B. Chaffin, J. P. Linderman, N. J. A. Sloane and Allan Wilks, On Curling Numbers of Integer Sequences, Journal of Integer Sequences, Vol. 16 (2013), Article 13.4.3.

Index entries for sequences related to curling numbers

Formula

a(n) = 2*A093371(2n-1).

a(n) = 2*A211966(n-1), n >= 2.

Crossrefs

Bisection of A122536.

Cf. A093371, A211966, A216955, A216958.

Sequence in context: A028329 A204678 A025227 * A119430 A074034 A268952

Adjacent sequences: A211962 A211963 A211964 * A211966 A211967 A211968

Keyword

nonn

Author

Omar E. Pol, Nov 28 2012

Status

approved