A293749 Number of sets of nonempty words with a total of n letters over denary 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, 17235, 63508, 242841, 959746, 3924747, 16551199, 71994097, 322098625, 1481655067, 6990945197, 33812067833, 167294687170, 846131720816, 4367249636291, 22985935628080, 123193976095986, 671862417595209, 3724122166971836

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)^A212916(j).

Crossrefs

Column k=10 of A293112.

Cf. A212916, A293740.

Sequence in context: A293746 A293747 A293748 * A293114 A322188 A317976

Adjacent sequences: A293746 A293747 A293748 * A293750 A293751 A293752

Keyword

nonn

Author

Alois P. Heinz, Oct 15 2017

Status

approved