# A084942 (b-file synthesized from sequence entry)
0 1
1 1
2 9
3 216
4 9936
5 745200
6 82717200
7 12738448800
8 2598643555200
9 678245967907200
10 220429939569840000
11 87290256069656640000
12 41375581377017247360000
13 23128949989752641274240000