# A001799 (b-file synthesized from sequence entry)
2 8
3 72
4 2160
5 15504
6 220248
7 1564920
8 89324640
9 640807200
10 9246847896
11 67087213336
12 1957095947664
13 14342471475696
14 211153052281080
15 1560676296310488
16 185256494416099008
17 1379131680653181504
18 20598677144877854232