# A012403 (b-file synthesized from sequence entry)
2 2
3 -3
4 0
5 -10
6 -32
7 1596
8 -10080
9 27936
10 -260928
11 1924560
12 33929280
13 -686630880
14 4846421760
15 -42426084960
16 778331473920
17 -1890071554560
18 -216298842931200
19 4070252020032000
20 -41366803088056320