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

Author

Omar E. Pol, Nov 28 2012

Keywords

• nonn

Comments

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

Links

• 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

Crossrefs

Bisection of A122536.

Cf. A093371, A211966, A216955, A216958.

Formula

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

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