# A012921 (b-file synthesized from sequence entry)
0 1
1 4
2 16
3 184
4 8320
5 529824
6 52633728
7 7595502464
8 1487529832448
9 380497987834368
10 123182327672588288
11 49234752596303947776
12 23812565081465676070912
13 13707078729819239829938176