# A309221 (b-file synthesized from sequence entry)
0 1
1 2
2 23
3 240
4 2355
5 22320
6 205942
7 1866592
8 16664147
9 147164464
10 1287061400
11 11174456704
12 96362903378
13 826641224992
14 7055950608008
15 59990171328640
16 508090131646771
17 4290071141315376
18 36113651041694280
19 303253863622924416
20 2540231448366573400