# A117643 (b-file synthesized from sequence entry)
0 3
1 2
2 2
3 3
4 8
5 35
6 204
7 1421
8 11360
9 102231
10 1022300
11 11245289
12 134943456
13 1754264915
14 24559708796
15 368395631925
16 5894330110784
17 100203611883311
18 1803665013899580
19 34269635264092001
20 685392705281840000