# A213231 (b-file synthesized from sequence entry)
0 1
1 1
2 4
3 25
4 176
5 1431
6 12526
7 117850
8 1167446
9 12080563
10 129326575
11 1422908670
12 15999766613
13 183070661566
14 2124252427416
15 24929036429880
16 295250330398281
17 3523043486823439
18 42294807342916249
19 510274778010082846
20 6181011777164665559
21 75112032752942278141