%I A056512
%S A056512 0,0,0,0,0,0,0,0,0,1,1,13,21,154,266
%N A056512 Periodic palindromic structures using exactly six different symbols.
%D A056512 M. R. Nester (1999). Mathematical investigations of some plant interaction 
               designs. PhD Thesis. University of Queensland, Brisbane, Australia.
%F A056512 A056507(n)-A056506(n).
%e A056512 For example, aaabbb is not a (finite) palindrome but it is a periodic 
               palindrome. Permuting the symbols will not change the structure.
%Y A056512 Cf. A056475.
%Y A056512 Sequence in context: A053659 A066630 A147435 this_sequence A056523 A158998 
               A122559
%Y A056512 Adjacent sequences: A056509 A056510 A056511 this_sequence A056513 A056514 
               A056515
%K A056512 nonn
%O A056512 1,12
%A A056512 Marks R. Nester (nesterm(AT)dpi.qld.gov.au)