A036781 a(n) = n + Sum_{k=0..n} k!.

1, 3, 6, 13, 38, 159, 880, 5921, 46242, 409123, 4037924, 43954725, 522956326, 6749977127, 93928268328, 1401602636329, 22324392524330, 378011820620331, 6780385526348332, 128425485935180333, 2561327494111820334, 53652269665821260335, 1177652997443428940336

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..400

Crossrefs

A003422[ n ] + n.

Cf. A007489.

Programs

Maple

a:= proc(n) option remember; `if`(n=0, 1, a(n-1)+1+n!) end:
seq(a(n), n=0..30);  # Alois P. Heinz, Jan 05 2015

Mathematica

Module[{nn=30,f},f=Accumulate[Range[0,nn]!];Table[n+f[[n]],{n,nn}]]-1 (* Harvey P. Dale, Nov 04 2020 *)
Module[{nn=30,f},f=Accumulate[Range[0,nn]!];Total/@Thread[{f,Range[0,nn]}]] (* Harvey P. Dale, Jan 31 2023 *)