# A143508 (b-file synthesized from sequence entry)
0 1
1 1
2 2
3 9
4 52
5 372
6 3058
7 28074
8 282028
9 3059328
10 35497672
11 437499541
12 5696752234
13 78036803430
14 1120687989348
15 16823652188164
16 263345788211608
17 4289062071449610
18 72543038644585822
19 1271980596430351862
20 23085579883157411532
21 433071407705851089244