A136760 a(n) = leading digit of n! in base 9.

1, 1, 2, 6, 2, 1, 8, 6, 6, 6, 6, 8, 1, 1, 2, 4, 8, 1, 3, 7, 1, 4, 1, 2, 7, 2, 6, 2, 7, 2, 8, 3, 1, 4, 1, 7, 3, 1, 6, 3, 1, 7, 3, 1, 1, 5, 3, 1, 1, 5, 3, 2, 1, 8, 5, 3, 2, 1, 1, 8, 6, 4, 3, 2, 2, 1, 1, 1, 1, 7, 6, 6, 5, 4, 4, 4, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 5, 5, 6, 7, 8, 1, 1, 1, 1, 2, 2

Offset: 0

Author

Carl R. White, Jan 21 2008

Keywords

• base
• easy
• nonn

Examples

			a(10) = 6 as 10! = 6740700_9 which has leading digit 6. - _David A. Corneth_, Jan 15 2021
		

Links

• David A. Corneth, Table of n, a(n) for n = 0..9999

Crossrefs

Cf. A000142, A136696, A136754, A136755, A136756, A136757, A136758, A136759, A008905, A136761, A136762, A136763, A136764, A136765, A136766.

Programs

Mathematica

f[n_]:=First[IntegerDigits[n!,9]]; lst={};Do[AppendTo[lst,f[n]],{n,0,2*5!}];lst (* Vladimir Joseph Stephan Orlovsky, Jun 14 2009 *)
IntegerDigits[#,9][[1]]&/@(Range[0,100]!) (* Harvey P. Dale, Jun 21 2021 *)

PARI

a(n) = digits(n!, 9)[1]; \\ Michel Marcus, Jan 27 2015