A056523 - OEIS

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

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OFFSET

1,12

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

FORMULA

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

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

EXAMPLE

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.

CROSSREFS

Column 6 of A285037.

Cf. A056485, A056512, A056516, A056517.

Sequence in context: A269309 A203854 A325448 * A056512 A362098 A158998

Adjacent sequences: A056520 A056521 A056522 * A056524 A056525 A056526

KEYWORD

nonn

AUTHOR

Marks R. Nester

EXTENSIONS

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

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

STATUS

approved