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A327387
Number of colored integer partitions of n such that nine colors are used and parts differ by size or by color.
6
1, 9, 54, 246, 945, 3186, 9729, 27414, 72315, 180415, 429156, 979425, 2155485, 4593330, 9510624, 19188360, 37815948, 72950634, 138002024, 256405887, 468550278, 843138585, 1495634373, 2617905474, 4525424256, 7731765279, 13065217956, 21849902348, 36184992984
OFFSET
9,2
FORMULA
a(n) ~ exp(Pi*sqrt(3*n)) * 3^(1/4) / (64 * n^(3/4)). - Vaclav Kotesovec, Sep 16 2019
G.f.: (-1 + Product_{k>=1} (1 + x^k))^9. - Ilya Gutkovskiy, Jan 31 2021
MAPLE
b:= proc(n, i, k) option remember; `if`(n=0, 1, `if`(i<1, 0, add((t->
b(t, min(t, i-1), k)*binomial(k, j))(n-i*j), j=0..min(k, n/i))))
end:
a:= n-> (k-> add(b(n$2, k-i)*(-1)^i*binomial(k, i), i=0..k))(9):
seq(a(n), n=9..45);
MATHEMATICA
A327387[n_] := SeriesCoefficient[(Product[(1 + x^k), {k, 1, n}] - 1)^9, {x, 0, n}]; Table[A327387[n], {n, 9, 37}] (* Robert P. P. McKone, Jan 31 2021 *)
CROSSREFS
Column k=9 of A308680.
Sequence in context: A250286 A289254 A059597 * A282920 A023008 A079817
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Sep 03 2019
STATUS
approved