# A109581 (b-file synthesized from sequence entry)
0 0
1 1
2 -2
3 6
4 0
5 -120
6 1440
7 -10080
8 40320
9 362880
10 -10886400
11 159667200
12 -1437004800
13 0
14 348713164800
15 -9153720576000
16 146459529216000
17 -1067062284288000
18 -25609494822912000
19 1338096104497152000
20 -34060628114472960000
21 510909421717094400000