# A020097 (b-file synthesized from sequence entry)
0 1
1 1
2 2
3 4
4 13
5 61
6 346
7 2326
8 17973
9 156849
10 1525708
11 16366685
12 191936577
13 2442829157
14 33533382056
15 493855262997
16 7766996408942
17 129920667204110
18 2303139100436493
19 43131514062719763
20 850867141055471684