# A047159 (b-file synthesized from sequence entry)
0 1
1 3
2 13
3 72
4 417
5 2509
6 15438
7 96310
8 607231
9 3859594
10 24689329
11 158756701
12 1025210362
13 6644336882
14 43193144567
15 281525730152
16 1839132807282
17 12038672624172
18 78943126865652
19 518485130526736
20 3410150902046028