# A324137 (b-file synthesized from sequence entry)
0 1
1 1
2 2
3 6
4 24
5 120
6 720
7 5020
8 39790
9 352470
10 3445032
11 36775404
12 425282892
13 5292245764
14 70471602994
15 999394962306
16 15032677450752
17 238984379214960
18 4002966472631160
19 70448661940661068
20 1299478739106621670
21 25067231918730741438
22 504674373639695198712
23 10584965637367018566180