# A091033 (b-file synthesized from sequence entry)
2 1
3 180
4 25200
5 4233600
6 898128000
7 239740300800
8 79332244992000
9 32011868528640000
10 15509750302126080000
11 8898339094906060800000
12 5971815866682429603840000
13 4637851802955964809216000000