A330632 Number of n-bead bracelets using exactly three colors with no adjacent beads having the same color.

0, 0, 1, 3, 3, 10, 9, 27, 29, 75, 93, 221, 315, 684, 1095, 2247, 3855, 7682, 13797, 27009, 49939, 96906, 182361, 352695, 671091, 1296855, 2485533, 4806075, 9256395, 17920857, 34636833, 67159047, 130150587, 252745365, 490853415, 954637555, 1857283155

Offset

1,4

Links

Andrew Howroyd, Table of n, a(n) for n = 1..500

Crossrefs

Column 3 of A330341.

Cf. A208539.

Sequence in context: A286570 A134704 A057210 * A278832 A168376 A266221

Adjacent sequences: A330629 A330630 A330631 * A330633 A330634 A330635

Keyword

nonn

Author

Andrew Howroyd, Dec 21 2019

Status

approved