# A275871 (b-file synthesized from sequence entry)
0 1
1 1
2 4
3 15
4 61
5 272
6 1317
7 6865
8 38278
9 227093
10 1426921
11 9457918
12 65898275
13 481177881
14 3672102116
15 29218285875
16 241873478425
17 2079079678176
18 18524191138689
19 170803860905237
20 1627465240969382