A293748 Number of sets of nonempty words with a total of n letters over nonary alphabet such that within each prefix of a word every letter of the alphabet is at least as frequent as the subsequent alphabet letter.

1, 1, 2, 6, 15, 45, 136, 430, 1415, 4845, 17234, 63497, 242720, 958754, 3916799, 16493831, 71586602, 319336319, 1463096806, 6869041635, 33014439494, 162130576595, 812715417240, 4151894763819, 21595739171153, 114222733829429, 613789962584588, 3347502798880170

Offset

0,3

Links

Alois P. Heinz, Table of n, a(n) for n = 0..1000

Formula

G.f.: Product_{j>=1} (1+x^j)^A212915(j).

Crossrefs

Column k=9 of A293112.

Cf. A212915, A293739.

Sequence in context: A293745 A293746 A293747 * A293749 A293114 A322188

Adjacent sequences: A293745 A293746 A293747 * A293749 A293750 A293751

Keyword

nonn

Author

Alois P. Heinz, Oct 15 2017

Status

approved