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%I #8 Jun 07 2018 22:06:20
%S 3,6,8,15,30,67,126,261,540,1101,2442
%N Number of length-n cyclic ternary words containing no abelian cubes.
%C Two words are considered identical in the cyclic sense if one is a cyclic shift of the other.
%C An abelian cube is a word of the form x x' x'' where x' and x'' are permutations of x.
%e For n = 4 the a(4) = 15 such words are {0011, 0012, 0021, 0022, 0101, 0102, 0112, 0121, 0122, 0202, 0211, 0212, 0221, 1122, 1212}.
%K nonn,more
%O 1,1
%A _Jeffrey Shallit_, Jun 05 2018
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