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%I #8 Oct 25 2019 16:39:27
%S 1,1,2,3,7,11,33,73,237,703,2433,8309,30108,108991,403262,1497070,
%T 5607437,21076571,79595990,301492045,1145560579,4363503684,
%U 16660204452,63741248201,244339646708,938255682551,3608668388957,13900021844558,53614340398327,207062143625711
%N Number of bracelet structures using a maximum of four different colored beads.
%C Turning over will not create a new bracelet. Permuting the colors of the beads will not change the structure.
%D 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]
%H Andrew Howroyd, <a href="/A056354/b056354.txt">Table of n, a(n) for n = 0..200</a>
%F Use de Bruijn's generalization of Polya's enumeration theorem as discussed in reference.
%F a(n) = Sum_{k=1..4} A152176(n, k) for n > 0. - _Andrew Howroyd_, Oct 25 2019
%Y Cf. A056292, A152176.
%K nonn
%O 0,3
%A _Marks R. Nester_
%E a(0)=1 prepended and terms a(26) and beyond from _Andrew Howroyd_, Oct 25 2019