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A320754
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Number of partitions of n with eight kinds of 1.
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2
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1, 8, 37, 129, 376, 966, 2258, 4902, 10026, 19520, 36459, 65721, 114877, 195454, 324706, 528069, 842531, 1321214, 2039553, 3103562, 4660814, 6914927, 10144558, 14728160, 21176077, 30171935, 42625765, 59741868, 83105140, 114790422, 157500479, 214739450
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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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G.f.: 1/(1-x)^8 * 1/Product_{j>1} (1-x^j).
Euler transform of 8,1,1,1,... .
a(n) ~ 2^(3/2) * 3^3 * n^(5/2) * exp(Pi*sqrt(2*n/3)) / Pi^7. - Vaclav Kotesovec, Oct 24 2018
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MAPLE
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a:= proc(n) option remember; `if`(n=0, 1, add(
(numtheory[sigma](j)+7)*a(n-j), j=1..n)/n)
end:
seq(a(n), n=0..40);
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MATHEMATICA
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nmax = 50; CoefficientList[Series[1/((1-x)^7 * Product[1-x^k, {k, 1, nmax}]), {x, 0, nmax}], x] (* Vaclav Kotesovec, Oct 24 2018 *)
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PROG
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(PARI) x='x+O('x^40); Vec(1/((1-x)^8*prod(j=2, 40, 1-x^j))) \\ G. C. Greubel, Oct 27 2018
(Magma) m:=40; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-x)^8*(&*[1-x^j: j in [2..30]])))); // G. C. Greubel, Oct 27 2018
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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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