

A053564


Number of ternary Lyndon words of length n with trace 1 and subtrace 2 over GF(3). Same as the number of ternary Lyndon words of length n with trace 2 and subtrace 2 over GF(3).


5



0, 0, 1, 3, 6, 13, 36, 93, 243, 645, 1782, 4914, 13608, 37890, 106288, 299025, 844182, 2391363, 6797196, 19371684, 55345784, 158486625, 454795398, 1307541690, 3765720066, 10862647236, 31381059609, 90780960426, 262951692390
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OFFSET

1,4


LINKS

Table of n, a(n) for n=1..29.
F. Ruskey, Ternary Lyndon words of given trace and subtrace over GF(3)


FORMULA

(1/n) Sum mu(d) M(n/d, 1, 2); dn, d=1, 2(3) where M(n, t, s) = Sum n!/(i!j!k!); i+j+k=n, j=t(3), k=s(3).


EXAMPLE

a(4) = 3 = { 0112, 0121, 0211 }


CROSSREFS

Cf. A053548, A053560, A053561, A053562, A053563.
Sequence in context: A201951 A104448 A062466 * A264236 A216999 A036781
Adjacent sequences: A053561 A053562 A053563 * A053565 A053566 A053567


KEYWORD

nonn


AUTHOR

Frank Ruskey, Jan 17 2000


STATUS

approved



