# A187742 (b-file synthesized from sequence entry)
0 1
1 1
2 4
3 14
4 66
5 384
6 2640
7 20880
8 186480
9 1854720
10 20321280
11 243129600
12 3153427200
13 44068147200
14 660064204800
15 10548573235200
16 179151388416000
17 3222109642752000
18 61178237632512000
19 1222853377794048000
20 25667116186263552000
21 564433265896980480000
22 12977099311614197760000