Which is the smallest number that you cannot score with 3 darts which all hit the dartboard (other than 1 and 2)?

Question

If you have to finish with a double in a game of darts, which number has the most number of different ways of finishing with 2 darts? (for instance 20 could be 18 and double 1, double 8 and double 2, treble 2 and double 7 etc )

Answer 1

163 is the smallest impossible score with three dart hits
1, 2, 166, 169, 172, 173, 175, 176, 178, 179 are the other impossible scores.