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A261743
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Number of partitions of n where each part i is marked with a word of length i over a nonary alphabet whose letters appear in alphabetical order.
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2
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1, 9, 126, 1299, 14211, 136611, 1373127, 12838293, 122478147, 1129559068, 10495764324, 95773104459, 877873080195, 7963150929030, 72400207009635, 654588661768353, 5924851016703093, 53460853371243261, 482688774419853026, 4350478100196378069, 39224153751141474936
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OFFSET
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0,2
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LINKS
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FORMULA
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a(n) ~ c * 9^n, where c = Product_{k>=2} 1/(1 - binomial(k+8,8)/9^k) = 3.23950351986835655716873222462341048089067679826... - Vaclav Kotesovec, Oct 11 2017, updated May 10 2021
G.f.: Product_{k>=1} 1 / (1 - binomial(k+8,8)*x^k). - Ilya Gutkovskiy, May 10 2021
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MAPLE
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b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0,
b(n, i-1)+`if`(i>n, 0, b(n-i, i)*binomial(i+8, 8))))
end:
a:= n-> b(n$2):
seq(a(n), n=0..30);
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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