A056348 Number of primitive (period n) bracelets using exactly two different colored beads.

0, 1, 2, 3, 6, 8, 16, 24, 42, 69, 124, 208, 378, 668, 1214, 2220, 4110, 7630, 14308, 26931, 50944, 96782, 184408, 352450, 675180, 1296477, 2493680, 4805388, 9272778, 17919558, 34669600

Offset

1,3

Comments

Turning over will not create a new bracelet. Identical to A001371 for n>1.

References

M. R. Nester (1999). Mathematical investigations of some plant interaction designs. PhD Thesis. University of Queensland, Brisbane, Australia. [See A056391 for pdf file of Chap. 2]

Links

Table of n, a(n) for n=1..31.

Formula

Sum mu(d)*A056342(n/d) where d divides n.

Crossrefs

Cf. A001037.

Sequence in context: A141348 A334269 A029867 * A308546 A324737 A057574

Adjacent sequences: A056345 A056346 A056347 * A056349 A056350 A056351

Keyword

nonn

Author

Marks R. Nester

Status

approved