A032069 Number of reversible strings with n labeled beads of 2 colors, no palindromes of more than 1 bead.

2, 2, 12, 144, 1440, 20160, 282240, 4838400, 87091200, 1799884800, 39597465600, 965667225600, 25107347865600, 708585150873600, 21257554526208000, 682919861944320000, 23219275306106880000

Offset

1,1

Links

Table of n, a(n) for n=1..17.

C. G. Bower, Transforms (2)

Formula

"BHJ" (reversible, identity, labeled) transform of 2, 0, 0, 0...

n! * A032085.

Crossrefs

Sequence in context: A087220 A032320 A032227 * A003090 A032152 A032057

Adjacent sequences: A032066 A032067 A032068 * A032070 A032071 A032072

Keyword

nonn

Author

Christian G. Bower

Status

approved