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A045627 Number of 2n-bead black-white reversible strings with n black beads and fundamental period 2n. 0
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified April 5 20:30 EDT 2020. Contains 333260 sequences. (Running on oeis4.)