my $p = 1;
for (my $i=2;;$i++) {
    my $k = ($i%2==0)?$i/2:$i;
    my $c = 0;
    for (my $j=1;$j<=$k;$j++) {
	$c++ if ($k % $j == 0);
    }
    my $d = $p*$c;
    if ($d>=500) {
	print "($i-1)*$i/2 has $d divisors\n";
	last;
    }
    $p = $c;
}