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A245795
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Number of preferential arrangements of n labeled elements when at least k=10 elements per rank are required.
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4
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1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 184757, 705433, 1998725, 4992289, 11618957, 25852921, 55791791, 117832681, 245039011, 503891821, 5552024604991, 46933238932021, 261680950107511, 1205121760579981, 4959685199012641, 18947093053200193
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OFFSET
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0,21
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LINKS
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FORMULA
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E.g.f.: 1/(2 + x - exp(x) + x^2/2! + x^3/3! + x^4/4! + x^5/5! + x^6/6! + x^7/7! + x^8/8! + x^9/9!). - Vaclav Kotesovec, Aug 02 2014
a(n) ~ n! / ((1+r^9/9!) * r^(n+1)), where r = 4.320434975980068857383128... is the root of the equation 2 + r - exp(r) + r^2/2! + r^3/3! + r^4/4! + r^5/5! + r^6/6! + r^7/7! + r^8/8! + r^9/9! = 0. - Vaclav Kotesovec, Aug 02 2014
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MAPLE
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a:= proc(n) option remember; `if`(n=0, 1,
add(a(n-j)*binomial(n, j), j=10..n))
end:
seq(a(n), n=0..40);
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MATHEMATICA
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CoefficientList[Series[1/(2 + x - E^x + x^2/2! + x^3/3! + x^4/4! + x^5/5! + x^6/6! + x^7/7! + x^8/8! + x^9/9!), {x, 0, 40}], x]*Range[0, 40]! (* Vaclav Kotesovec, Aug 02 2014 *)
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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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