# A005175 (b-file synthesized from sequence entry)
1 0
2 0
3 3
4 131
5 1830
6 16990
7 127953
8 851361
9 5231460
10 30459980
11 170761503
12 931484191
13 4979773890
14 26223530970
15 136522672653
16 704553794621
17 3611494269120
18 18415268221960
19 93516225653403
20 473366777478651
21 2390054857197150
22 12043393363764950
23 60590148885015753