A351360 Number of binary necklaces with n beads and at least three consecutive black beads.

0, 0, 1, 2, 3, 5, 9, 17, 31, 60, 113, 220, 419, 813, 1565, 3033, 5855, 11358, 21977, 42644, 82675, 160517, 311609, 605551, 1176871, 2288964, 4453237, 8669002, 16881859, 32892459, 64112225, 125022545, 243898335, 476011102, 929387453, 1815322932

Offset

1,4

Links

Table of n, a(n) for n=1..36.

Marko R. Riedel et al., Necklaces made of black and white beads, Math StackExchange, Feb 2022.

Formula

a(n) = A000031(n) - A093305(n).

Crossrefs

Cf. A351356, A351357, A351358, A351359, A351361.

Sequence in context: A383968 A014743 A345234 * A080889 A049858 A092483

Adjacent sequences: A351357 A351358 A351359 * A351361 A351362 A351363

Keyword

nonn

Author

Marko Riedel, Feb 08 2022

Status

approved