# A005977 (b-file synthesized from sequence entry)
1 0
2 0
3 0
4 0
5 1
6 2
7 7
8 31
9 168
10 1025
11 7013
12 52495
13 425213
14 3696032
15 34291937
16 338161526
17 3532185118
18 38963334652
19 452704892533
20 5526901638291
21 70746674291507