Fibonacci with & without memoizer

fibo.js

var limit = 100000000
var fibonacci = function(n) {
  if (typeof fibonacci.count === 'undefined') {
    fibonacci.count = 0
  }
  fibonacci.count += 1
  return n < 2 ? n : fibonacci(n - 1) + fibonacci(n - 2)
}

var start = new Date().getTime()
console.log("Let's go !")
var i   = 0,
    f   = fibonacci(i),
    sum = 0

while( f < limit ) {
  if ( f % 2 === 0 ) sum += f
  i += 1
  f = fibonacci(i)
}
console.log('//', i, ':', f)
console.log('//sum:', sum)
console.log('Total computing time : ', new Date().getTime() - start, "ms")
console.log('Total call : ', fibonacci.count)

var fibonacci = function() {
  var memo = [0, 1]
  var fib = function(n) {
    if (typeof fib.count === 'undefined') {
      fib.count = 0
    }
    fib.count += 1

    var result = memo[n]
    if (typeof result !== 'number'){
      result = fib(n - 1) + fib(n - 2)
      memo[n] = result
    }
    return result
  }
  return fib
}()

var memoizer = function(memo, formula){
  var recur = function(n) {
    if (typeof recur.count === 'undefined') {
      recur.count = 0
    }
    recur.count += 1
    var result = memo[n]
    if (typeof result !== 'number') {
      result = formula(recur, n)
      memo[n] = result
    }
    return result
  }
  return recur
}

var fibonacci = memoizer([0, 1], function(recur, n){
  return recur(n - 1) + recur(n - 2)
})

var start = new Date().getTime()
console.log("Let's go !")

var i   = 0,
    f   = fibonacci(i),
    sum = 0

while( f < limit ) {
  if ( f % 2 === 0 ) sum += f
  i += 1
  f = fibonacci(i)
}
console.log('//', i, ':', f)
console.log('//sum:', sum)

console.log('Total computing time : ', new Date().getTime() - start, "ms")
console.log('Total call : ', fibonacci.count)

// Output on my laptop
// Let's go !
// // 40 : 102334155
// //sum: 82790070
// Total computing time :  7619 ms
// Total call :  866988831
// Let's go !
// 40 : 102334155
// //sum: 82790070
// Total computing time :  0 ms
// Total call :  119