# A006819 (b-file synthesized from sequence entry)
0 1
1 6
2 30
3 150
4 750
5 3726
6 18438
7 90966
8 447918
9 2201622
10 10809006
11 52999446
12 259668942
13 1271054982
14 6218232414
15 30399142614