39937

15
8, 7, 13, 10, 6, 12, 9
1,14,6,17 -2 +2 -2 +2 -2 +2 -2 <--this is the sequence
2,13,7,16 6, 9, 11, 12, 4, 14 ,7
3,12 8,15,1,17
4,11 9,14,2,16
5,10,10 When you consider both of the first
numbers in both solutions e.g.
6,9,11,12,4,14,7 6-2=4 that does not work
11,12,4,14,7 8+2=10 that does not work either
7,8,12,11,5,13,8
8,7,13,10,6,12,9
9,6,149
10,5,15,8,8
11,4,16
12,3,17 <-- These are sll the combinations up to fifteen there are no more.
13,2,18
14,1,19
15,0