A045627 Number of 2n-bead black-white reversible strings with n black beads and fundamental period 2n.

1, 1, 3, 9, 34, 125, 459, 1715, 6432, 24300, 92375, 352715, 1352034, 5200299, 20058297, 77558625, 300540160, 1166803109, 4537567188, 17672631899, 68923264250, 269128935495, 1052049481857, 4116715363799, 16123801834656

Offset

0,3

Links

Table of n, a(n) for n=0..24.

Formula

Moebius transform of A032123(n+1) (Christian Bower).

Crossrefs

Sequence in context: A149007 A053791 A296223 * A007722 A149008 A149009

Adjacent sequences: A045624 A045625 A045626 * A045628 A045629 A045630

Keyword

nonn

Author

David W. Wilson

Status

approved