# A027149 (b-file synthesized from sequence entry)
2 1
3 10
4 42
5 352
6 1360
7 11616
8 43680
9 381952
10 1416960
11 12620800
12 46441472
13 419512320
14 1535352832
15 14021353472
16 51117465600
17 470886645760
18 1711716106240
19 15879295991808
20 57592095965184
21 537381547540480
22 1945481074704384