A292724 Number of multisets of nonempty words with a total of n letters over 9-ary alphabet such that within each word every letter of the alphabet is at least as frequent as the subsequent alphabet letter.
1, 1, 4, 14, 67, 343, 2151, 14900, 119259, 1055520, 6837054, 49975756, 358031350, 2673108092, 20399335633, 161247005007, 1321885836686, 10814140769210, 93349395210404, 726371063425227, 5939975798740967, 48195816632614079, 396235068140514442
Offset: 0
Keywords
Links
- Alois P. Heinz, Table of n, a(n) for n = 0..1000
Programs
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Maple
b:= proc(n, i, t) option remember; `if`(t=1, 1/n!, add(b(n-j, j, t-1)/j!, j=i..n/t)) end: a:= proc(n) option remember; `if`(n=0, 1, add(add(d*d!* b(d, 0, 9), d=numtheory[divisors](j))*a(n-j), j=1..n)/n) end: seq(a(n), n=0..35);