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A060688
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Number of dissimilar ternary squarefree words of length n+1.
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3
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1, 2, 3, 5, 7, 10, 13, 18, 24, 34, 44, 57, 76, 103, 133, 174, 232, 305, 398, 530, 691, 903, 1172, 1533, 1982, 2581, 3370, 4404, 5737, 7477, 9741, 12687, 16546, 21586, 28091
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| cycle b-> c-> b and a-> b-> c-> a to get 6 similar words in A006156(n+2)
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REFERENCES
| N. Wirth, Systematisches Programmieren, 1975, ch. 15.4, table 15.68
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EXAMPLE
| ab~ac (cycle b,c), ab~bc~ca and ac~ba~cb (cycle a,b,c) => a(1) = 6/6 = 1
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CROSSREFS
| a(n) := A006156(n+2)/6.
Sequence in context: A118199 A088318 A038083 * A005691 A172491 A035954
Adjacent sequences: A060685 A060686 A060687 * A060689 A060690 A060691
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KEYWORD
| nonn,more
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AUTHOR
| Frank Ellermann (Frank.Ellermann(AT)t-online.de), Apr 19 2001
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