login
A141148
Number of aperiodic ternary necklaces with n beads of each color and no adjacent beads of the same color.
2
2, 3, 14, 65, 346, 1929, 11442, 70310, 445928, 2896239, 19186738, 129184583, 881808726, 6089840427, 42482905678, 298976072384, 2120377458898, 15141288786096, 108784152585234, 785869928763325, 5705406374237814
OFFSET
1,1
LINKS
L. Q. Eifler, K. B. Reid Jr., D. P. Roselle, Sequences with adjacent elements unequal, Aequationes Mathematicae 6 (2-3), 1971.
FORMULA
a(n) = Sum_{d|n} moebius(n/d) * A141147(d) / n.
CROSSREFS
KEYWORD
nonn
AUTHOR
Max Alekseyev, Jun 10 2008
STATUS
approved