# A107307 (b-file synthesized from sequence entry)
0 1
1 4
2 15
3 51
4 183
5 655
6 2381
7 8653
8 31539
9 114927
10 419001
11 1527457
12 5568791
13 20302171
14 74016909
15 269846637
16 983794491
17 3586668535
18 13076103713
19 47672218297
20 173801058495
21 633635426355
22 2310077203221
23 8421966964069