# A026389 (b-file synthesized from sequence entry)
2 1
3 8
4 49
5 272
6 1440
7 7428
8 37730
9 189808
10 948909
11 4724160
12 23453001
13 116207424
14 575036475
15 2842936320
16 14046869575
17 69378730880
18 342590699955
19 1691519468760
20 8351553940355
21 41235710124400
22 203617691311370
23 1005560117623204