# A012698 (b-file synthesized from sequence entry)
0 0
1 0
2 2
3 -3
4 16
5 -50
6 248
7 -504
8 -1584
9 94536
10 -1464768
11 23328360
12 -336539040
13 5198852880
14 -79862710800
15 1306170600840
16 -21763435223040
17 382939844024640
18 -6915154663557120
19 130859230589792640