A056464 Number of primitive (aperiodic) palindromes using exactly three different symbols.

0, 0, 0, 0, 6, 6, 36, 36, 150, 144, 540, 534, 1806, 1770, 5790, 5760, 18150, 17994, 55980, 55830, 170970, 170466, 519156, 518580, 1569744, 1567944, 4733670, 4732014, 14250606, 14244660, 42850116, 42844320, 128746410, 128728800

Offset

1,5

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

Andrew Howroyd, Table of n, a(n) for n = 1..200

Formula

a(n) = Sum_{d|n} mu(d)*A056454(n/d).

Maple

with(numtheory):with(combinat, stirling2):A056454:=n->3!*stirling2(floor((n+1)/2), 3); A056464:=n->add(mobius(d)*A056454(n/d), d=divisors(n)); # C. Ronaldo

Crossrefs

Column 3 of A327873.

Cf. A056454, A056459.

Sequence in context: A165827 A256136 A111437 * A056454 A056452 A183622

Adjacent sequences: A056461 A056462 A056463 * A056465 A056466 A056467

Keyword

nonn

Author

Marks R. Nester

Status

approved