# A331500 (b-file synthesized from sequence entry)
0 1
1 2
2 120
3 20880
4 7244160
5 4193683200
6 3648171985920
7 4450790792448000
8 7251098441261875200
9 15208619045076276019200
10 39919072914444753469440000
11 128188338317208930555828633600
12 494389344738688341547326898176000
13 2255096937522349816552823932846080000