JSFiddle - React, Tailwind, and code Playground

JavaScript

function gcd(a, b) {
    var t;
    if (a > b) {
        t = a;
        a = b;
        b = t;
    }
    // a <= b
   	t = b % a;
    return t ? gcd(t, a) : a;
}

function lcm(a, b) {
	return a * b / gcd(a, b);
}

var LCM = lcm(1, 2);
for (var k = 3; k <= 20; k++) {
	LCM = lcm(k, LCM);
	console.log(k, LCM);
}