OP solved it, closing

Not a issue

You need to flatten your return array.

damn it. I did this in like 10 lines of code. now i see you can do it in one

This isn't an issue with the kata. Run through what your code does using console.log(arr) at the end of each iteration and you should see why it doesn't pass the second test.

Thanks! To be honest I think your solution will be more efficient, but when I was writing this I was probably in a functional programming mood :-)

cool!!

so cool

lol @ dodekeract