Smallest number divisible by a series of continuous whole numbers starting from 1

gistfile1.aw

<?php

/* Greatest Common Divisor */
function gcd($x, $y) {
	if ($y === 0) return $x;
	return abs(gcd($y, $x % $y));
}

/* Least Common Multiples */
function lcm($x, $y) {
	return $x * $y / gcd($x, $y);
}

function recursive_lcm($z) {
	if ($z <= 0) return false;
	if ($z === 2) return 2;
	return lcm($z, recursive_lcm($z-1) );
}

echo recursive_lcm(20);

?>