# A020028 (b-file synthesized from sequence entry)
0 1
1 0
2 0
3 0
4 1
5 4
6 20
7 121
8 862
9 7000
10 63876
11 646743
12 7195013
13 87239530
14 1145018832
15 16173391002
16 244622538903
17 3944538439806
18 67550220781672
19 1224347751667801
20 23415650750646696
21 471239971356764754