# A052653 (b-file synthesized from sequence entry)
0 1
1 1
2 2
3 18
4 120
5 1320
6 15120
7 216720
8 3427200
9 62052480
10 1237420800
11 27263174400
12 653837184000
13 17005993804800
14 476080648243200
15 14283727121664000
16 457058345103360000
17 15540339420942336000