A056477 Number of primitive (aperiodic) palindromic structures using a maximum of three different symbols.

1, 1, 0, 1, 1, 4, 3, 13, 12, 39, 36, 121, 116, 364, 351, 1088, 1080, 3280, 3237, 9841, 9800, 29510, 29403, 88573, 88440, 265716, 265356, 797121, 796796, 2391484, 2390352, 7174453, 7173360, 21523238, 21520080, 64570064, 64566684, 193710244, 193700403, 581130368, 581120880

Offset

0,6

Comments

Permuting the symbols will not change the structure.

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 = 0..500

Formula

a(n) = Sum_{d|n} mu(d)*A124302(ceiling(n/(2*d))) for n > 0.

a(n) = Sum_{k=1..3} A284826(n, k) for n > 0. - Andrew Howroyd, Oct 02 2019

Crossrefs

Cf. A007051, A124302, A056459, A284826.

Sequence in context: A370924 A120340 A082018 * A105200 A088933 A019136

Adjacent sequences: A056474 A056475 A056476 * A056478 A056479 A056480

Keyword

nonn

Author

Marks R. Nester

Extensions

a(0)=1 prepended and terms a(32) and beyond from Andrew Howroyd, Oct 02 2019

Status

approved