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URL: https://oeis.org/A365973

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A365973
Expansion of e.g.f. exp( Sum_{k>=0} x^(4*k+3) / (4*k+3) ).
1
1, 0, 0, 2, 0, 0, 40, 720, 0, 2240, 172800, 3628800, 246400, 49420800, 3531340800, 87223136000, 18450432000, 3006222336000, 225434879488000, 6411312940032000, 2744461025280000, 435228787435520000, 35074217524469760000, 1126838040745697280000
OFFSET
0,4
FORMULA
a(0) = 1; a(n) = (n-1)! * Sum_{k=0..floor((n-3)/4)} a(n-4*k-3)/(n-4*k-3)!.
PROG
(PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(exp(sum(k=0, N\4, x^(4*k+3)/(4*k+3)))))
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Sep 23 2023
STATUS
approved