A336955 a(n) = Sum_{k=0..n} k^k * binomial(n, k)^2.

1, 2, 9, 73, 849, 12651, 228493, 4836301, 117204545, 3196763983, 96842596701, 3224356269597, 116981406934417, 4591908332288837, 193846634326107701, 8755364023207809301, 421214258699748184321, 21500563181275847468503, 1160430732790051008442141, 66020998289431649938896445

Offset

0,2

Links

Table of n, a(n) for n=0..19.

Mathematica

a[n_] := 1 + Sum[k^k * Binomial[n, k]^2, {k, 1, n}]; Array[a, 20, 0] (* Amiram Eldar, Aug 09 2020 *)

Prog

(PARI) {a(n) = sum(k=0, n, k^k*binomial(n, k)^2)}

Crossrefs

Cf. A037966, A037972, A086331, A329913, A329444, A336828.

Sequence in context: A184358 A132843 A346648 * A084873 A332722 A103996

Adjacent sequences: A336952 A336953 A336954 * A336956 A336957 A336958

Keyword

nonn

Author

Seiichi Manyama, Aug 09 2020

Status

approved