# A025131 (b-file synthesized from sequence entry)
2 2
3 24
4 238
5 2180
6 19184
7 164864
8 1395230
9 11683212
10 97083652
11 802098704
12 6597442768
13 54074559968
14 441952039104
15 3603658886144
16 29327060440350
17 238277193572828
18 1933262776766876