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

Author

Marks R. Nester

Keywords

• nonn

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

Crossrefs

Column 3 of A327873.

Cf. A056454, A056459.

Programs

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

Formula

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