A318687 Number of length-n circular binary words having exactly n distinct blocks of length floor(log_2(n)) + 1 (A070939).

2, 1, 2, 3, 2, 3, 4, 12, 14, 17, 14, 13, 12, 20, 32, 406, 538, 703, 842, 1085, 1310, 1465, 1544, 1570, 1968, 2132, 2000, 2480, 2176, 2816, 4096, 1060280

Offset: 1

Author

Jeffrey Shallit, Aug 31 2018

Keywords

• nonn
• more

Comments

A "circular word" (a.k.a. "necklace") is one that wraps around from the end to the beginning. The words are counted up to an equivalence where two circular words are the same if one is a cyclic shift of the other.

Links

• D. Gabric, S. Holub, and J. Shallit, Generalized de Bruijn words and the state complexity of conjugate sets, arXiv:1903.05442 [cs.FL], March 13 2019.

Crossrefs

Cf. A317586, which studies a similar quantity for two different lengths of blocks.

Cf. A070939.

Formula

a(2^n-1) = 2^(2^(n-1)-n+1) since A317586(2^n) = 2^(2^(n-1)-n) and A317586(2^n-1) = A317586(2^n+1) = 2*A317586(2^n) = 2^(2^(n-1)-n+1). - Altug Alkan, Sep 05 2018