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A320550
Number of partitions of n into parts of exactly eight sorts which are introduced in ascending order such that sorts of adjacent parts are different.
3
1, 29, 492, 6401, 70880, 704676, 6490951, 56524414, 471750268, 3810085913, 29989229889, 231255237342, 1754111872952, 13128442914265, 97189645391839, 713050007293418, 5192646586543845, 37581376345173772, 270593146238709314, 1939929376873532436
OFFSET
8,2
LINKS
FORMULA
a(n) ~ 7^(n-1) / (7! * QPochhammer[1/7]). - Vaclav Kotesovec, Oct 25 2018
MAPLE
b:= proc(n, i, k) option remember; `if`(n=0 or i=1, k^(n-1),
b(n, i-1, k) +`if`(i>n, 0, k*b(n-i, i, k)))
end:
A:= (n, k)-> `if`(n=0, 1, `if`(k<2, k, k*b(n$2, k-1))):
a:= n-> (k-> add(A(n, k-i)*(-1)^i/(i!*(k-i)!), i=0..k))(8):
seq(a(n), n=8..40);
CROSSREFS
Column k=8 of A262495.
Cf. A258463.
Sequence in context: A261540 A173986 A258462 * A211833 A022753 A225969
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Oct 15 2018
STATUS
approved