# A037704 (b-file synthesized from sequence entry)
1 1
2 9
3 54
4 326
5 1957
6 11745
7 70470
8 422822
9 2536933
10 15221601
11 91329606
12 547977638
13 3287865829
14 19727194977
15 118363169862
16 710179019174
17 4261074115045
18 25566444690273
19 153398668141638
20 920392008849830
21 5522352053098981