# A216712 (b-file synthesized from sequence entry)
0 1
1 1
2 4
3 22
4 140
5 514
6 3444
7 23790
8 165932
9 774610
10 5767268
11 42526198
12 310791884
13 1574532626
14 12230311188
15 92980917006
16 696528653740
17 3677761305954
18 29231321098692
19 226211978983190
20 1720430261953036
21 9313977313216354
22 75106192841523892
23 588010633850768622