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A336228
a(0) = 1; a(n) = Sum_{k=0..n-1} binomial(n,k)^2 * (n-k) * a(k).
1
1, 1, 6, 75, 1684, 59005, 2977566, 204512875, 18346977608, 2083115635065, 291996210173410, 49525220811387871, 9996609976117991436, 2368117724291275331869, 650613686811158069472942, 205196311013650099853516115, 73633144885479474283911225616
OFFSET
0,3
FORMULA
a(n) = (n!)^2 * [x^n] 1 / (1 - sqrt(x) * BesselI(1,2*sqrt(x))).
MATHEMATICA
a[0] = 1; a[n_] := a[n] = Sum[Binomial[n, k]^2 (n - k) a[k], {k, 0, n - 1}]; Table[a[n], {n, 0, 16}]
nmax = 16; CoefficientList[Series[1/(1 - Sqrt[x] BesselI[1, 2 Sqrt[x]]), {x, 0, nmax}], x] Range[0, nmax]!^2
CROSSREFS
Sequence in context: A126462 A081066 A185289 * A326011 A350283 A350411
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Jul 12 2020
STATUS
approved