A349962 a(n) = Sum_{k=0..n} (2*k)^k.
1, 3, 19, 235, 4331, 104331, 3090315, 108503819, 4403471115, 202762761483, 10442762761483, 594761064172811, 37115108500229387, 2518267981703965963, 184577387811646500107, 14533484387811646500107, 1223459304002440821206283, 109651494909968373175414027
Offset: 0
Links
- Seiichi Manyama, Table of n, a(n) for n = 0..351
Programs
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Mathematica
a[n_] := Sum[If[k == 0, 1, (2*k)^k], {k, 0, n}]; Array[a, 18, 0] (* Amiram Eldar, Dec 07 2021 *) -
PARI
a(n) = sum(k=0, n, (2*k)^k);
Formula
a(n) ~ 2^n * n^n. - Vaclav Kotesovec, Dec 07 2021
Comments