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

0,2

Comments

Partial sums of A062971.

Links

Seiichi Manyama, Table of n, a(n) for n = 0..351

Formula

a(n) ~ 2^n * n^n. - Vaclav Kotesovec, Dec 07 2021

Mathematica

a[n_] := Sum[If[k == 0, 1, (2*k)^k], {k, 0, n}]; Array[a, 18, 0] (* Amiram Eldar, Dec 07 2021 *)

Prog

(PARI) a(n) = sum(k=0, n, (2*k)^k);

Crossrefs

Cf. A062970, A062971, A349961, A349963, A349970.

Sequence in context: A228229 A323875 A001929 * A230316 A157675 A355216

Adjacent sequences: A349959 A349960 A349961 * A349963 A349964 A349965

Keyword

nonn,easy

Author

Seiichi Manyama, Dec 07 2021

Status

approved