$"++;_:while(++$"){$"%$_||next(_)for 2..$"-1;print$",$/}

##</code><code>##

$"++;_:while(++$"){$"%$_||next(_)for 2..sqrt$";print$",$/}

##</code><code>##

$"++;_:while(++$"){$"%$_||next(_)for 2..$"/2;print$",$/}