# A375796 (b-file synthesized from sequence entry)
0 1
1 1
2 2
3 6
4 36
5 240
6 1800
7 15960
8 164640
9 1905120
10 24343200
11 342619200
12 5269017600
13 87749101440
14 1573083832320
15 30218175187200
16 619256461824000
17 13483023576422400
18 310821905134540800
19 7563477205380096000
20 193736838233562624000
21 5210638309494858240000