A127554 Sum of the digits of left factorial !n.

0, 1, 2, 4, 1, 7, 10, 19, 19, 19, 19, 28, 37, 37, 55, 55, 37, 46, 46, 73, 73, 64, 82, 100, 100, 118, 109, 100, 127, 127, 145, 118, 163, 145, 154, 172, 172, 154, 181, 181, 199, 172, 226, 208, 253, 226, 262, 262, 253, 271, 235, 271, 262, 280, 325, 325, 307, 343, 334

Offset: 0

Author

Paolo P. Lava and Giorgio Balzarotti, Apr 17 2007

Keywords

• easy
• nonn
• base

Examples

			!5 = 0!+1!+2!+3!+4! = 1+1+2+6+24 = 34 --> 3+4=7.
		

Links

• Seiichi Manyama, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A003422, A004152, A007953.

Programs

Maple

P:=proc(n) local a,i,k,w; a:=0; for i from 1 by 1 to n do w:=0;k:=(i-1)!+a; a:=k; while k>0 do w:=w+k-(trunc(k/10)*10); k:=trunc(k/10); od; print(w); od; end: P(100);

Mathematica

Array[Total[IntegerDigits[Total[Range[0,#-1]!]]]&,59,0] (* James C. McMahon, Jan 01 2025 *)

Formula

a(n) = A007953(A003422(n)). - R. J. Mathar, Apr 22 2007