This is an absolutely great write up and I really appreciate you taking the time to write all that down for us!

Needs some tests with noncorrect words thrown in to up the difficulty

Great solution. I forgot all about that array with pipe regex concept!

So the inner loop is the prime factors for a single number, then the outer loop is repeating the process for all the numbers from 2..n? Trying to wrap my head around the concept.

because index of a range starts at zero, an n length range starting at i will go from i to i + n-1

This is very creative and a great idea!

oh man, i love this solution

Still learning regex, can you explain the positive lookahead with nothing to look ahead to? Why does split(/[A-Z]/) not work?

How many words out there have 5000 letters?

I like these problems that are more 'real world' than the ridiculous math problems that dominate this place

I'm just a noob and still learning but I don't understand how this meets the problem of the digits needing to be in increasing order. For instance say, 245 == 11 and 542 == 11 but only 245 would meet the criteria of the problem as described at the top of the description. Does the way this solution works account for this? I'm just curious because I'm trying to learn, not nitpick :)

exactly