i'm posting this just to show some different code. The methodolgy doesn't use factorials per se, just lists of numbers. There are probably some ways to optimize, but i don't have enough time to really try right now.

sub c{
   my($c,$d)=@_;my%n=map{$_=>1}1..$c;delete$n{$_}for 1..($c-$d);
   eval join'/',map"($_)",(join'*',keys%n),(join'*',1..$d)
}
[download]

It's warnings and strict compliant, and returns all the right answers.

nuf evah,
jynx