JSFiddle - React, Tailwind, and code Playground

HTML

<div id="log"></div>

JavaScript

function log(n) {$("#log").html($("#log").html()+"<br>"+n);}

function fib(n) {
    var a = 2;
    var b = 1
    var c = 0
    for(i = 0; i <= n; i++) {
        c = a;
        a = a + b;
        b = c;
    
     
fib(20);