%I #43 Jan 03 2016 19:51:26
%S 0,1,1170,1528,9877,9886,9897,11535
%N The decimal digits of n appear n times in the decimal representation of n!.
%C There are no more terms up to n=21000, checked using the Python program below.
%C a(9) > 200000. - _Dana Jacobsen_, Jan 03 2016
%e 1170 belongs to this sequence because the digits 1, 7 and 0 appear 1170 times in total in the decimal representation of 1170!.
%e 0! = 1, which contains no zeros, so 0 is a term.
%o (Python)
%o from math import factorial
%o def in_a(n):
%o ....f = str(factorial(n))
%o ....s = set(str(n))
%o ....return sum(f.count(d) for d in s)==n
%o (Perl) use ntheory ":all"; sub is_a264688 { my $n = shift; $n == eval "factorial($n) =~ tr/[$n]//"; } # _Dana Jacobsen_, Jan 03 2016
%K nonn,base,more
%O 1,3
%A _Christian Perfect_, Jan 03 2016