A248827 Row sums of A187783 and A089759.

1, 2, 3, 5, 15, 137, 4393, 518625, 239478123, 455196345315, 4054931519864889, 157048983466046778713, 33902817175022723879495899, 33209307490198775518644207834495, 202452250996395056747517509528867065999

Offset: 0

Author

Tilman Piesk, Oct 28 2014

Keywords

• nonn

Examples

			          1                  1
        1   1                2
      1   1   1              3
    1   2   1   1            5
  1   6   6   1   1         15
1  24  90  20   1   1      137
		

Links

• Tilman Piesk, Table of n, a(n) for n = 0..53

Programs

Mathematica

Table[Sum[((n-k)*k)! / (k!)^(n-k), {k, 0, n}], {n, 0, 15}] (* Vaclav Kotesovec, Nov 24 2023 *)

Formula

log(a(n)) ~ n^2 * (log(n/2)/4 + 1/(16*log(n))). - Vaclav Kotesovec, Nov 24 2023