fibfast.js

// map supports has(key), get(key) and set(key, val)
const fib = (n, memo = new Map()) => {
  if (memo.has(n)) return memo.get(n);
  if (n <= 1) return 1;
  memo.set(n, fib(n-1, memo) + fib(n-2, memo));
  return memo.get(n);
};
for(let i = 0; i <= 1476; i++) {
  console.log(i, fib(i));
}
// fib(1476 is Infinity for js)