A036782 a(n) = n - 1 + Sum_{j=0..n} j!.

0, 2, 5, 12, 37, 158, 879, 5920, 46241, 409122, 4037923, 43954724, 522956325, 6749977126, 93928268327, 1401602636328, 22324392524329, 378011820620330, 6780385526348331, 128425485935180332, 2561327494111820333

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn

Crossrefs

Cf. A036781.

Programs

Maple

N:= 30: # to get a(0) to a(N)
C:= ListTools:-PartialSums([seq(j!,j=0..N)]):
seq(n-1+C[n+1],n=0..N); # Robert Israel, Jan 05 2015

PARI

a(n) = n - 1 + sum(j=0, n, j! ); \\ Joerg Arndt, Jan 06 2015

Formula

a(n) = A036781(n) - 1.

E.g.f.: exp(x-1)*(Ei(1)-Ei(1-x)) + exp(x)*(x-1) + 1/(1-x). - Robert Israel, Jan 05 2015