A045509 Factorials having initial digit '1'.

1, 120, 1307674368000, 121645100408832000, 1124000727777607680000, 15511210043330985984000000, 10888869450418352160768000000, 10333147966386144929666651337523200000000, 13763753091226345046315979581580902400000000

Offset: 1

Author

Jeff Burch

Keywords

• nonn
• base

Comments

Benford's law shows that this sequence will contain about log 2/log 10 =~ 30% of factorials. [Charles R Greathouse IV, Nov 13 2010]

Links

• Index entries for sequences related to Benford's law

Crossrefs

For factorials with initial digit d (1 <= d <= 9) see A045509, A045510, A045511, A045516, A045517, A045518, A282021, A045519; A045520, A045521, A045522, A045523, A045524, A045525, A045526, A045527, A045528, A045529.

Cf. A000142.

Programs

Mathematica

Select[Range[40]!,First[IntegerDigits[#]]==1&] (* Harvey P. Dale, Aug 06 2013 *)

Formula

a(n) = A000142(A045520(n+1)). - Amiram Eldar, Jul 19 2020

Extensions

Corrected and extended by Harvey P. Dale, Aug 06 2013