I think this gets the job done.
function leastCommonMultiple(min, max) {
function range(min, max) {
var arr = [];
for (var i = min; i <= max; i++) {
arr.push(i);
}
return arr;
}
function gcd(a, b) {
return !b ? a : gcd(b, a % b);
}
function lcm(a, b) {
return (a * b) / gcd(a, b);
}
var multiple = min;
range(min, max).forEach(function(n) {
multiple = lcm(multiple, n);
});
return multiple;
}
leastCommonMultiple(1, 13); // => 360360