A056269 Number of primitive (aperiodic) words of length n which contain exactly four different symbols.

0, 0, 0, 24, 240, 1560, 8400, 40800, 186480, 818280, 3498000, 14674440, 60780720, 249393480, 1016542560, 4123132800, 16664094960, 67171179600, 270232006800, 1085569963080, 4356217672800, 17466683473800

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]

Crossrefs

Cf. A000302, A000919, A054719.

Formula

sum mu(d)*A000919(n/d) where d|n.

Seems to be n * A056289.