Perl 6 is very generous in this:

pugs> sub postfix:<!> (Int $n) { [*] 1..$n }
undef
pugs> say $_! for ^10
1
1
2
6
24
120
720
5040
40320
362880
undef
[download]

(I personally believe that I've posted this before here and in different media, but that's jut because it's quite about the only thing I can actually do in pugs ATM.)