A141148 Number of aperiodic ternary necklaces with n beads of each color and no adjacent beads of the same color.

2, 3, 14, 65, 346, 1929, 11442, 70310, 445928, 2896239, 19186738, 129184583, 881808726, 6089840427, 42482905678, 298976072384, 2120377458898, 15141288786096, 108784152585234, 785869928763325, 5705406374237814

Offset: 1

Author

Max Alekseyev, Jun 10 2008

Keywords

• nonn

Links

• L. Q. Eifler, K. B. Reid Jr., D. P. Roselle, Sequences with adjacent elements unequal, Aequationes Mathematicae 6 (2-3), 1971.
• Max Alekseyev, PARI scripts for various problems

Crossrefs

Cf. A110706, A110707, A110710, A110711, A141146, A141147.

Formula

a(n) = Sum_{d|n} moebius(n/d) * A141147(d) / n.