A136760 - OEIS

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

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,3

LINKS

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

EXAMPLE

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

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 *)

PROG

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