As well, not optimised in most of the browsers, can exit with Maximum call stack size exceeded error

Long to enumerate all the variants
If you have fourbonacci, would you add another if-condition?

It's not optimised in all browsers and can exit with Maximum call stack size exceeded error

It's not readable and you cannot easily debug it

Slow as it's recursive
Yet not all recursive code is optimized well

It's slow, you can do O(1) algorithm

It's O(N^2) where N - number of letters in str

formatTime is created every time you call G964.stat
You can make it static as well

How does that work?
I don't understand

Recreating a lot of strings
Working longer with strings like: {([{([...])}])}
For the example, it takes N / 2 times to create string with s.replace

As thinking of the implementation of String.prototype.replace it has O(N^2) complexity
You can do better

Best solution!
Looks short and precise!