A074656 Number of Lyndon words (aperiodic necklaces) with 4n beads of 4 colors, n beads of each color.

1, 6, 312, 30798, 3941280, 586637250, 96197630040, 16875655269942, 3111284137104000, 595909785174026400, 117634021776545937000, 23797087019979071174574, 4912693780461256332795168, 1031629572413246016139181538, 219809927417367517614451764984

Offset

0,2

Links

Table of n, a(n) for n=0..14.

Index entries for sequences related to Lyndon words

Formula

1/(4n) * sum over d|n of {mu(n/d) * (4d)! / d!^4}.

Example

For n=1 the 6 words are 0123 0132 0213 0231 0312 0321 . - R. J. Mathar, Oct 21 2021

Crossrefs

a(n)=A029809(n)*6. a(n) = A074652(n)/4.

Sequence in context: A282373 A123181 A281932 * A233108 A207816 A204462

Adjacent sequences: A074653 A074654 A074655 * A074657 A074658 A074659

Keyword

nonn

Author

Christian G. Bower, Aug 29 2002

Extensions

a(0)=1 prepended by Alois P. Heinz, Aug 24 2015

Status

approved