A056465 Number of primitive (aperiodic) palindromes using exactly four different symbols.

0, 0, 0, 0, 0, 0, 24, 24, 240, 240, 1560, 1560, 8400, 8376, 40824, 40800, 186480, 186240, 818520, 818280, 3497976, 3496440, 14676024, 14674440, 60780720, 60772320, 249401640, 249393480, 1016542800, 1016501736, 4123173624, 4123132800, 16664093400, 16663908480

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 4 of A327873.

Cf. A056455, A056460.

Formula

a(n) = Sum_{d|n} mu(d)*A056455(n/d).

Extensions

Terms a(31) and beyond from Andrew Howroyd, Sep 28 2019