Ah, I should think a bit more before submitting. Here is a 44 (and I should also mention it only works for smallish natural numbers, all different and at least 2 arguments):

sub nn{$a|=2x$_.3for@_;$b.=2until$a=~/3$b(3)/;@a=@-}

The need for the assign is a perlbug, otherwise it would be 41