# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a056335 Showing 1-1 of 1 %I A056335 #6 Aug 22 2017 20:53:09 %S A056335 1,1,3,9,31,112,466,2124,10476,55058,301632,1703989,9819215,57364723, %T A056335 338134486,2005132504,11937364183,71254885362,426063226936, %U A056335 2550552259119,15280103806730,91588103894781 %N A056335 Number of primitive (aperiodic) reversible string structures with n beads using a maximum of six different colors. %C A056335 A string and its reverse are considered to be equivalent. Permuting the colors will not change the structure. %D A056335 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 A056335 Sum mu(d)*A056325(n/d) where d|n. %Y A056335 Cf. A056317. %K A056335 nonn %O A056335 1,3 %A A056335 _Marks R. Nester_ # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE