# A113995 (b-file synthesized from sequence entry)
0 1
1 4
2 16
3 64
4 276
5 1304
6 6808
7 39320
8 250752
9 1759604
10 13530928
11 113522192
12 1034613180
13 10199679712
14 108334569184
15 1235056156832
16 15059906315120
17 195775382409972
18 2705084927865600
19 39616257445460560
20 613348477806011476