January 2017 Fiendish Function

The Fiendish Function posed during January 2017 had the following sample guesses and replies:

  • GUESS
  • REPLY
  • 1
  • 2
  • 2
  • 16
  • 3
  • 512
  • 4
  • 66
  • 5
  • 36
  • 10
  • 4

The rule was: "Square the number, then add 2 to the power of the digits together".

Suppose the guess was 13:

  • Square the number, giving 169.
  • Take the number's digits, giving 1, 6, 9
  • Take 2 to the power of each digit, giving 2, 64, 512
  • Add these together, giving 578.

So the result is 578.