## February 2018 Fiendish Function

The Fiendish Function posed during February 2018 had the following sample guesses and replies:

- 1
- 3
- 2
- 9
- 3
- 19
- 4
- 33
- 5
- 51
- 10
- 201

The rule was: "Two times the number squared plus one".

Suppose the guess was 12:

- Take 2 times the number squared, giving 288
- Add 0 times the number, giving 288
- Add 1, giving 289

So the result is 289.

## Earlier answers

Here are the answers to the Fiendish Functions posted in earlier months: