# A003807 (b-file synthesized from sequence entry)
1 168
2 5616
3 20160
4 372000
5 1876896
6 16482816
7 42456960
8 212427600
9 270178272
10 1425715200
11 6950204928
12 5644682640
13 78156525216
14 50778000000
15 282027786768
16 499631102880
17 283991644800
18 1098404364288