# A181337 (b-file synthesized from sequence entry)
0 0
1 1
2 6
3 28
4 123
5 512
6 2064
7 8124
8 31416
9 119820
10 451972
11 1689532
12 6268276
13 23107836
14 84721796
15 309151932
16 1123431812
17 4067533244
18 14679173444
19 52821023932
20 189571527236
21 678748381372
22 2424976195396
23 8646702275772