# A143340 (b-file synthesized from sequence entry)
0 1
1 1
2 4
3 15
4 84
5 402
6 2520
7 13339
8 88484
9 494814
10 3395816
11 19657398
12 137999048
13 818024484
14 5836517808
15 35201610387
16 254231733188
17 1553691459558
18 11327637588552
19 69948932919906
20 513856752260184
21 3199802098978428