OFFSET
1,1
COMMENTS
The asymptotic density of this sequence is log_10(4/3) = 0.124938... (Kunoff, 1987). - Amiram Eldar, Jul 17 2020
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..10000
Sharon Kunoff, N! has the first digit property, The Fibonacci Quarterly, Vol. 25, No. 4 (1987), pp. 365-367.
FORMULA
A008905(a(n)) = 3. - Amiram Eldar, Jul 17 2020
EXAMPLE
9 is a term since 9! = 362880 has the initial digit 3.
MATHEMATICA
Select[ Range[ 500 ], IntegerDigits[ #! ] [ [ 1 ] ] == 3 & ]
PROG
(PARI) isok(n) = digits(n!)[1] == 3; \\ Michel Marcus, Feb 07 2017
CROSSREFS
KEYWORD
nonn,base
AUTHOR
STATUS
approved