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A362161
Expansion of e.g.f. exp(-x * sqrt(1-4*x)).
2
1, -1, 5, -1, 121, 1039, 20221, 416975, 10573361, 309650399, 10335294901, 386839539679, 16045117551145, 730346985279599, 36191355037097261, 1939288174467052079, 111724538085236200801, 6886112439557645126335, 452112545350761238085221
OFFSET
0,3
FORMULA
a(n) = (-1)^n * n! * Sum_{k=0..n} 4^k * binomial((n-k)/2,k)/(n-k)!.
a(n) ~ 2^(2*n - 5/2) * n^(n-1) / exp(n). - Vaclav Kotesovec, Apr 10 2023
PROG
(PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(exp(-x*sqrt(1-4*x))))
CROSSREFS
Cf. A362158.
Sequence in context: A113114 A356051 A099740 * A359657 A133002 A272755
KEYWORD
sign,easy
AUTHOR
Seiichi Manyama, Apr 10 2023
STATUS
approved