

A056514


Number of primitive (period n) periodic palindromic structures using a maximum of three different symbols.


5



1, 1, 1, 1, 3, 4, 9, 13, 28, 39, 84, 121, 244, 364, 741, 1088, 2200, 3280, 6591, 9841, 19720, 29510, 59169, 88573, 177240, 265716, 531804, 797121, 1594684, 2391484, 4783968, 7174453, 14350000, 21523238, 43050000, 64570064, 129143196, 193710244, 387430329, 581130368, 1162271280
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,5


COMMENTS

For example, aaabbb is not a (finite) palindrome but it is a periodic palindrome. 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..200


FORMULA

a(n) = Sum_{dn} mu(d)*A056504(n/d) for n > 0.
Moebius transform of A056504.
a(n) = Sum_{k=1..3} A285037(n, k) for n > 0.  Andrew Howroyd, Apr 08 2017


CROSSREFS

Cf. A056477, A056504, A285037.
Sequence in context: A000624 A244703 A232801 * A151517 A219043 A050163
Adjacent sequences: A056511 A056512 A056513 * A056515 A056516 A056517


KEYWORD

nonn


AUTHOR

Marks R. Nester


EXTENSIONS

Corrected by Franklin T. AdamsWatters and T. D. Noe, Oct 25 2006
a(17)a(35) from Andrew Howroyd, Apr 08 2017
a(0)=1 prepended and terms a(36) and beyond from Andrew Howroyd, Oct 01 2019


STATUS

approved



