%I A056523
%S A056523 0,0,0,0,0,0,0,0,0,1,1,13,21,154,266
%N A056523 Number of primitive (period n) periodic palindromic structures using 
               exactly six different symbols.
%D A056523 M. R. Nester (1999). Mathematical investigations of some plant interaction 
               designs. PhD Thesis. University of Queensland, Brisbane, Australia.
%F A056523 A056517(n)-A056516(n).
%e A056523 For example, aaabbb is not a (finite) palindrome but it is a periodic 
               palindrome. Permuting the symbols will not change the structure. 
               This should be different from A056512.
%Y A056523 Cf. A056485.
%Y A056523 Sequence in context: A066630 A147435 A056512 this_sequence A158998 A122559 
               A132131
%Y A056523 Adjacent sequences: A056520 A056521 A056522 this_sequence A056524 A056525 
               A056526
%K A056523 nonn
%O A056523 1,12
%A A056523 Marks R. Nester (nesterm(AT)dpi.qld.gov.au)