# A355287 (b-file synthesized from sequence entry)
0 1
1 0
2 0
3 6
4 12
5 40
6 1260
7 8568
8 62160
9 1473120
10 19111680
11 232626240
12 5403451680
13 103176028800
14 1822033204992
15 45916616592000
16 1129459815993600
17 26346457488798720
18 749439127417466880
19 22165051763204582400
20 640916967497214643200
21 20787453048015928350720