A lookup table implementation of the Fibonacci generator in JavaScript.

fibonacci-lookup.js

const lookup = [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610,
987, 1597, 2584, 4181, 6765, 10946, 17711, 28657, 46368, 75025, 121393,
196418, 317811, 514229, 832040, 1346269, 2178309, 3524578, 5702887, 9227465,
14930352, 24157817, 39088169, 63245986, 102334155, 165580141, 267914296,
433494437, 701408733, 1134903170, 1836311903, 2971215073, 4807526976,
7778742049, 12586269025, 20365011074, 32951280099, 53316291173, 86267571272,
139583862445, 225851433717, 365435296162, 591286729879, 956722026041,
1548008755920, 2504730781961, 4052739537881, 6557470319842, 10610209857723,
17167680177565, 27777890035288, 44945570212853, 72723460248141,
117669030460994, 190392490709135, 308061521170129, 498454011879264,
806515533049393, 1304969544928657, 2111485077978050, 3416454622906707,
5527939700884757, 8944394323791464];

function* fib (n = 79) {
  if (n > 79) throw new Error('Values are not available for n > 79.');
  yield* lookup.slice(0, n);
}