# A074502 (b-file synthesized from sequence entry)
0 3
1 9
2 41
3 225
4 1313
5 7809
6 46721
7 280065
8 1679873
9 10078209
10 60467201
11 362799105
12 2176786433
13 13060702209
14 78364180481
15 470185017345
16 2821109972993
17 16926659575809
18 101559956930561
19 609359740534785
20 3656158441111553