A264688 The decimal digits of n appear n times in the decimal representation of n!.

0, 1, 1170, 1528, 9877, 9886, 9897, 11535

Offset: 1

Author

Christian Perfect, Jan 03 2016

Keywords

• nonn
• base
• more

Comments

There are no more terms up to n=21000, checked using the Python program below.

a(9) > 200000. - Dana Jacobsen, Jan 03 2016

Examples

			1170 belongs to this sequence because the digits 1, 7 and 0 appear 1170 times in total in the decimal representation of 1170!.
0! = 1, which contains no zeros, so 0 is a term.
		

Programs

Perl

use ntheory ":all"; sub is_a264688 { my $n = shift; $n == eval "factorial($n) =~ tr/[$n]//"; } # Dana Jacobsen, Jan 03 2016

Python

from math import factorial
def in_a(n):
    f = str(factorial(n))
    s = set(str(n))
    return sum(f.count(d) for d in s)==n