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A380020
Expansion of e.g.f. 1/sqrt(exp(-2*x) - 2*x*exp(-x)).
0
1, 2, 8, 55, 540, 6861, 106828, 1968443, 41884496, 1010558161, 27259824996, 812935829355, 26556802948624, 943118750625377, 36176486632451012, 1490585029223430691, 65656827447552549504, 3078782615385684631809, 153127047650469476373316
OFFSET
0,2
FORMULA
a(n) = n! * Sum_{k=0..n} (-2)^k * (k+1)^(n-k) * binomial(-1/2,k)/(n-k)!.
PROG
(PARI) a(n) = n!*sum(k=0, n, (-2)^k*(k+1)^(n-k)*binomial(-1/2, k)/(n-k)!);
CROSSREFS
Sequence in context: A139016 A367753 A377098 * A134954 A087422 A081667
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Jan 09 2025
STATUS
approved