A056461 Number of primitive (aperiodic) palindromes using a maximum of five different symbols.

5, 0, 20, 20, 120, 100, 620, 600, 3100, 3000, 15620, 15480, 78120, 77500, 390480, 390000, 1953120, 1949900, 9765620, 9762480, 48827480, 48812500, 244140620, 244124400, 1220703000, 1220625000, 6103512500, 6103437480, 30517578120, 30517184400, 152587890620, 152587500000

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. A056391, A056451.

Column 5 of A284823.

Programs

PARI

a(n) = sumdiv(n, d, moebius(d)*5^((1 + n/d)\2));
for(n=1, 40, print1(a(n), ", ")); \\ Petros Hadjicostas, Apr 24 2020

Formula

Sum_{d|n} mu(d)*A056451(n/d).

Extensions

More terms from Petros Hadjicostas, Apr 24 2020