A053561 Number of ternary Lyndon words of length n with trace 0 and subtrace 2 over GF(3).

0, 1, 2, 3, 6, 15, 36, 87, 234, 645, 1782, 4893, 13608, 37994, 106434, 299025, 844182, 2391723, 6797196, 19369708, 55342972, 158486625, 454795398, 1307534319, 3765720066, 10862688116, 31381118658, 90780960426, 262951692390

Offset: 1

Author

Frank Ruskey, Jan 17 2000

Keywords

• nonn

Examples

			a(4) = 3 = |{ 0012, 0021, 0102 }|
		

Links

• F. Ruskey, Ternary Lyndon words with given trace and subtrace over GF(3)

Crossrefs

Cf. A053548, A053560, A053562, A053563, A053564.

Formula

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