A032321 Number of aperiodic necklaces with n labeled beads of 2 colors.

2, 2, 12, 72, 720, 6480, 90720, 1209600, 20321280, 359251200, 7424524800, 160465536000, 3923023104000, 101213996083200, 2853345470976000, 85364982743040000, 2742350070620160000, 93039294691639296000

Offset

1,1

Links

Table of n, a(n) for n=1..18.

C. G. Bower, Transforms (2)

Index entries for sequences related to Lyndon words

Formula

"CHJ" (necklace, identity, labeled) transform of 2, 0, 0, 0...

n! * A001037.

Crossrefs

Cf. A001037.

Sequence in context: A180072 A367546 A013315 * A013311 A303343 A087220

Adjacent sequences: A032318 A032319 A032320 * A032322 A032323 A032324

Keyword

nonn

Author

Christian G. Bower

Status

approved