# A006947 (b-file synthesized from sequence entry)
1 2
2 7
3 35
4 219
5 1594
6 12935
7 113945
8 1070324
9 10586856
10 109259633
11 1168384157
12 12877168147
13 145656436074
14 1685157199175
15 19886174611045
16 238819338399054
17 2913166800256664
18 36036122671902718
19 451429953643336590
20 5720172601392931006