A136763 a(n) = leading digit of n! in base 13.

1, 1, 2, 6, 1, 9, 4, 2, 1, 12, 9, 8, 7, 7, 8, 9, 11, 1, 1, 2, 3, 5, 9, 1, 2, 4, 9, 1, 3, 7, 1, 3, 7, 1, 3, 10, 2, 6, 1, 4, 1, 3, 10, 2, 9, 2, 8, 2, 8, 2, 9, 2, 11, 3, 1, 4, 1, 7, 2, 11, 4, 1, 6, 2, 12, 4, 1, 9, 3, 1, 8, 3, 1, 8, 3, 1, 9, 4, 2, 12, 5, 2, 1, 8, 4, 2, 1, 7, 3, 2, 1, 7, 4, 2, 1, 9, 5, 3, 1, 1

Offset: 0

Author

Carl R. White, Jan 21 2008

Keywords

• nonn
• easy
• base

Examples

			a(10) = 9 as 10! = 9100926_13 which has leading digit 9. - _David A. Corneth_, Jan 15 2021
		

Links

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

Crossrefs

Cf. A000142, A136699, A136754, A136755, A136756, A136757, A136758, A136759, A136760, A008905, A136761, A136762, A136764, A136765, A136766.

Programs

Mathematica

Table[First[IntegerDigits[n!,13]],{n,0,100}] (* Harvey P. Dale, Dec 20 2015 *)

PARI

a(n) = digits(n!, 13)[1]; \\ Michel Marcus, Jan 27 2015