%I #14 Sep 03 2018 15:42:08

%S 1,1,2,5,10,35,102,360,1232,4427,15934,58465,215250,799593,2983204,

%T 11187200,42109450,159081482,602809326,2290679807,8726308212,

%U 33318645341,127479700198,488672244040,1876500180280

%N Number of primitive (period n) n-bead necklace structures using a maximum of four different colored beads.

%C Turning over the necklace is not allowed. Colors may be permuted without changing the necklace 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]

%F a(n) = Sum_{d|n} mu(d) * A056292(n/d); mu = A008683.

%Y Cf. A008683, A027377, A056292.

%K nonn

%O 1,3

%A _Marks R. Nester_