# A013207 (b-file synthesized from sequence entry)
0 0
1 1
2 -2
3 4
4 -12
5 68
6 -440
7 3064
8 -26208
9 265936
10 -2945152
11 35730176
12 -485182720
13 7235106240
14 -115677206528
15 1984468240000
16 -36707903762432
17 725871298851072
18 -15190637885095936
19 336136505074527232