A056335 - OEIS

%I #6 Aug 22 2017 20:53:09

%S 1,1,3,9,31,112,466,2124,10476,55058,301632,1703989,9819215,57364723,

%T 338134486,2005132504,11937364183,71254885362,426063226936,

%U 2550552259119,15280103806730,91588103894781

%N Number of primitive (aperiodic) reversible string structures with n beads using a maximum of six different colors.

%C A string and its reverse are considered to be equivalent. Permuting the colors 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]

%F Sum mu(d)*A056325(n/d) where d|n.

%Y Cf. A056317.

%K nonn

%O 1,3

%A _Marks R. Nester_