A062807 a(n) = Sum_{i=1..n} i*(n-i)^i.

0, 1, 4, 14, 50, 187, 738, 3084, 13652, 63917, 315736, 1641314, 8956110, 51175799, 305527878, 1901829488, 12319405728, 82896050937, 578485474092, 4180313933206, 31237475311690, 241063266361235, 1918899090047882

Offset: 1

Author

Olivier Gérard, Jun 23 2001

Keywords

• nonn
• easy

Links

• Harry J. Smith, Table of n, a(n) for n = 1..200

Crossrefs

Cf. A101495.

Programs

Mathematica

Table[Sum[i (n-i)^i,{i,n}],{n,30}] (* Harvey P. Dale, Dec 25 2017 *)

PARI

a(n)={sum(i=1, n, i*(n - i)^i)} \\ Harry J. Smith, Aug 11 2009

Formula

G.f.: x*Sum_{k>=1} k*x^k/(1 - k*x)^2. - Ilya Gutkovskiy, Oct 11 2018

Extensions

Prior Mathematica program replaced by Harvey P. Dale, Dec 25 2017