The other kata tells you how to go from 156 to [6,7,11]. All you have to do is reverse that.

Of course, the input might have been 12345, so you'd get [3,4,5,6,5,6,7,7,8,9]. Could you get back from that to 12345 ?

Collecting some different inputs and outputs from the other kata might be useful; you might be able to spot patterns without trying to reverse the manipulations from first principles.

any non spoiler - hints?

Not giving out spoilers, sorry.

Was debating asking a question but I gave in :)

I did the other kata being mentioned here - but i'm still lost.
The previous kata returns the array and it looks like what's being passed in this funciton (sums) is that array.

How are we manipulating the array here [6,7,11] to get 156?

THATS why I'm so damned confused

Because 156 => [ 6, 7, 11 ]

This is the reverse of another kata. The top of the description is from that other kata.