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Hi, @rycharde, thank you for the problem and response. I should have triple checked before answering, especially when it was done by tapping solution on a phone and right before bed :p

The path 1-3 is flawed:
The last bit should be
2!+3!+3!=14, not a power of 2
2!+3!+4!=32 (2^5)
2!+3!+5!=128 (2^7)

Now the solution should be completed.

Thank you again for the interesting problem, I really enjoyed my time solving it ^_^

That's cool! We know that a,b and c cannot all be 3 or more, because the sum would then always be a multiple of 3, but one of them can be greater than 3.