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A056523
Number of primitive (period n) periodic palindromic structures using exactly six different symbols.
3
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
1,12
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
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.
Sequence in context: A269309 A203854 A325448 * A056512 A362098 A158998
KEYWORD
nonn
EXTENSIONS
a(16)-a(26) from Andrew Howroyd, Apr 09 2017
Terms a(27) and beyond from Andrew Howroyd, Oct 01 2019
STATUS
approved