A121880 a(n) = 2^n - A122536(n).

0, 2, 4, 10, 20, 44, 88, 182, 364, 738, 1476, 2972, 5944, 11924, 23848, 47768, 95536, 191214, 382428, 765136, 1530272, 3061104, 6122208, 12245530, 24491060, 48984342, 97968684, 195941804, 391883608, 783776080, 1567552160, 3135122038, 6270244076

Offset: 1

Author

N. J. A. Sloane, Sep 21 2006

Keywords

• nonn

Comments

Number of binary sequences of length n with curling number > 1. See A122536 for much more information.

Links

• Robert Price, Table of n, a(n) for n = 1..200
• B. Chaffin, J. P. Linderman, N. J. A. Sloane and Allan Wilks, On Curling Numbers of Integer Sequences, arXiv:1212.6102 [math.CO], 2012-2013.
• 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.
• Daniel Gabric, Jeffrey Shallit, Borders, Palindrome Prefixes, and Square Prefixes, arXiv:1906.03689 [cs.DM], 2019.
• Index entries for sequences related to curling numbers

Crossrefs

Cf. A122536. Similar to but different from A094536.

See also A093370.