A056523 Number of primitive (period n) periodic palindromic structures using exactly six different symbols.

0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 13, 21, 154, 266, 1488, 2646, 12857, 22827, 101484, 179487, 752646, 1323652, 5325226, 9321312, 36387267, 63436373, 242085494, 420693273, 1577870839, 2734926558, 10120484024, 17505749897, 64096919293, 110687251039, 401885411487

Offset: 1

Author

Marks R. Nester

Keywords

• nonn

Examples

			For example, aaabbb is not a (finite) palindrome but it is a periodic palindrome. Permuting the symbols will not change the structure. This should be different from A056512.
		

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 6 of A285037.

Cf. A056485, A056512, A056516, A056517.

Formula

a(n) = A056517(n) - A056516(n).

Moebius transform of A056512. - Andrew Howroyd, Oct 01 2019

Extensions

a(16)-a(26) from Andrew Howroyd, Apr 09 2017

Terms a(27) and beyond from Andrew Howroyd, Oct 01 2019