text: if (typeof window === 'undefined') {
    util = require(__dirname + '/../util.js');
  }
  
  var memo = [0, 1]; // our base cases
  
  function fib3(n) {
    if (typeof memo[n] === 'undefined') {
      memo[n] = fib3(n - 1) + fib3(n - 2); // memoization
    }
    return memo[n];
  }
  
  util.out(fib3(5));
  util.out(fib3(50));
  