# A094370 (b-file synthesized from sequence entry)
0 1
1 2
2 3
3 8
4 45
5 288
6 140
7 17280
8 14175
9 89600
10 299376
11 17418240
12 5255250
13 402361344000
14 2501928000
15 98402304
16 488462349375
17 342372925440000
18 2534852320000
19 5377993912811520000
20 4842604238472
21 29967718809600000