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A300512
Expansion of e.g.f. log(Sum_{k>=0} p(k)*x^k/k!), where p(k) = number of partitions of k (A000041).
3
0, 1, 1, -1, -1, 6, -1, -77, 203, 1344, -10692, -15862, 579611, -1518768, -32884753, 283168220, 1550435633, -38615194078, 44538307279, 4920513118440, -39485852954288, -546206846420721, 11322395643617278, 23746787652752639, -2713550731461618505, 17064642256532964421
OFFSET
0,6
COMMENTS
Logarithmic transform of A000041.
FORMULA
E.g.f.: log(Sum_{k>=0} A000041(k)*x^k/k!).
EXAMPLE
E.g.f.: A(x) = x/1! + x^2/2! - x^3/3! - x^4/4! + 6*x^5/5! - x^6/6! - 77*x^7/7! + 203*x^8/8! + ...
MAPLE
a:= proc(n) option remember; (t-> `if`(n=0, 0, t(n)-add(j*a(j)*
binomial(n, j)*t(n-j), j=1..n-1)/n))(combinat[numbpart])
end:
seq(a(n), n=0..30); # Alois P. Heinz, Mar 07 2018
MATHEMATICA
nmax = 25; CoefficientList[Series[Log[Sum[PartitionsP[k] x^k/k!, {k, 0, nmax}]], {x, 0, nmax}], x] Range[0, nmax]!
a[n_] := a[n] = PartitionsP[n] - Sum[k Binomial[n, k] PartitionsP[n - k] a[k], {k, 1, n - 1}]/n; a[0] = 0; Table[a[n], {n, 0, 25}]
CROSSREFS
KEYWORD
sign
AUTHOR
Ilya Gutkovskiy, Mar 07 2018
STATUS
approved