May 2017 Fiendish Function

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

  • GUESS
  • REPLY
  • 1
  • 4
  • 2
  • 15
  • 3
  • 40
  • 4
  • 85
  • 5
  • 156
  • 10
  • 1111

The rule was: "Cube the number, add the original number squared, add the original number, then add one".

Suppose the guess was 11:

  • Cube the number, giving 1331.
  • Add the original number squared, giving 1452.
  • Add the original number, giving 1463.
  • Add one, giving 1464.

So the result is 1464.