# A012886 (b-file synthesized from sequence entry)
0 1
1 2
2 3
3 8
4 30
5 121
6 493
7 2011
8 8204
9 33469
10 136540
11 557028
12 2272449
13 9270673
14 37820597
15 154292742
16 629451995
17 2567909604
18 10476032782
19 42737977489
20 174353665921
21 711292452431
22 2901785575960
23 11838111735997