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A355495
Expansion of Sum_{k>=0} (k^2 * x/(1 - x))^k.
3
1, 1, 17, 762, 67772, 10032208, 2226273192, 691431572992, 286268594755712, 152365547943819264, 101361042063083269520, 82409537565402784477984, 80397802305461995791664944, 92692687015689239272783171264
OFFSET
0,3
LINKS
FORMULA
a(n) = Sum_{k=1..n} k^(2*k) * binomial(n-1,k-1) for n > 0.
PROG
(PARI) my(N=20, x='x+O('x^N)); Vec(sum(k=0, N, (k^2*x/(1-x))^k))
(PARI) a(n) = if(n==0, 1, sum(k=1, n, k^(2*k)*binomial(n-1, k-1)));
CROSSREFS
Cf. A323280.
Sequence in context: A294757 A176233 A360647 * A368492 A012221 A012144
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Jul 04 2022
STATUS
approved