The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A053561 Number of ternary Lyndon words of length n with trace 0 and subtrace 2 over GF(3). 5
 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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS 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) EXAMPLE a(4) = 3 = |{ { 0012, 0021, 0102 }| CROSSREFS Cf. A053548, A053560, A053562, A053563, A053564. Sequence in context: A138477 A182240 A052102 * A237585 A147773 A006403 Adjacent sequences:  A053558 A053559 A053560 * A053562 A053563 A053564 KEYWORD nonn AUTHOR Frank Ruskey, Jan 17 2000 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 27 12:30 EDT 2020. Contains 337380 sequences. (Running on oeis4.)