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A261860 Number of compositions of n into distinct parts where each part i is marked with a word of length i over a nonary alphabet whose letters appear in alphabetical order and all letters occur at least once in the composition. 2
12607, 1850013, 13188465, 141059073, 1056825045, 9244127655, 358616974839, 1185100976313, 6776480736882, 31512728488918, 161603593094034, 844675656403032, 26805281002135578, 67485379090772970, 310715577607315770, 1129828504295753862, 4665897718158585321 (list; graph; refs; listen; history; text; internal format)
OFFSET
9,1
COMMENTS
Also number of matrices with nine rows of nonnegative integer entries and without zero rows or columns such that the sum of all entries is equal to n and the column sums are distinct.
LINKS
FORMULA
a(n) = A261836(n,9).
MAPLE
b:= proc(n, i, p, k) option remember;
`if`(i*(i+1)/2<n, 0, `if`(n=0, p!, b(n, i-1, p, k)+
`if`(i>n, 0, b(n-i, i-1, p+1, k)*binomial(i+k-1, k-1))))
end:
a:= n->(k->add(b(n$2, 0, k-i)*(-1)^i*binomial(k, i), i=0..k))(9):
seq(a(n), n=9..30);
CROSSREFS
Column k=9 of A261836.
Sequence in context: A246231 A248709 A352586 * A187136 A185841 A219332
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Sep 03 2015
STATUS
approved

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Last modified April 23 13:11 EDT 2024. Contains 371913 sequences. (Running on oeis4.)