%I A056493
%S A056493 2,1,2,3,6,7,14,18,28,39,62,81,126,175,246,360,510,728,1022,1485,2030,
%T A056493 3007,4094,6030,8184,12159,16352,24381,32766,48849,65534,97920,131006,
%U A056493 196095,262122,392364,524286,785407,1048446,1571310,2097150,3143497
%N A056493 Number of primitive (period n) periodic palindromes using a maximum of 
               two different symbols.
%C A056493 For example, aaabbb is not a (finite) palindrome but it is a periodic 
               palindrome.
%C A056493 Also aperiodic necklaces (Lyndon words) that are the same when turned 
               over.
%D A056493 M. R. Nester (1999). Mathematical investigations of some plant interaction 
               designs. PhD Thesis. University of Queensland, Brisbane, Australia.
%H A056493 <a href="Sindx_Lu.html#Lyndon">Index entries for sequences related to 
               Lyndon words</a>
%F A056493 Sum mu(d)*A029744(n/d) where d divides n.
%Y A056493 Cf. A056458.
%Y A056493 Sequence in context: A128474 A108618 A097719 this_sequence A001371 A001037 
               A122086
%Y A056493 Adjacent sequences: A056490 A056491 A056492 this_sequence A056494 A056495 
               A056496
%K A056493 nonn
%O A056493 1,1
%A A056493 Marks R. Nester (nesterm(AT)dpi.qld.gov.au)
%E A056493 More terms and additional comments from Christian G. Bower (bowerc(AT)usa.net), 
               Jun 22 2000