# A007555 (b-file synthesized from sequence entry)
0 1
1 1
2 2
3 6
4 23
5 107
6 586
7 3690
8 26245
9 207997
10 1817090
11 17345358
12 179595995
13 2004596903
14 23992185226
15 306497734962
16 4162467826729
17 59882101858777
18 909688617178178
19 14551535460258966
20 244477068964113407