# A062873 (b-file synthesized from sequence entry)
0 1
1 1
2 3
3 17
4 140
5 1623
6 23688
7 414292
8 8408768
9 193891685
10 5001814400
11 142675793706
12 4458289724928
13 151440666806527
14 5556047001924608
15 218947599027613688
16 9223382498249719808
17 413620308786882430089
18 19673207238835121651712
19 989209888652706998977990
20 52428801216451004088320000