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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.
5
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
FORMULA
G.f.: Product_{j>=1} (1+x^j)^A212915(j).
CROSSREFS
Column k=9 of A293112.
Sequence in context: A293745 A293746 A293747 * A293749 A293114 A322188
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Oct 15 2017
STATUS
approved