# A365880 (b-file synthesized from sequence entry)
0 1
1 1
2 6
3 21
4 116
5 566
6 3176
7 17501
8 101391
9 590756
10 3519782
11 21163038
12 128845344
13 790810400
14 4894134376
15 30486741869
16 191068074202
17 1203710067455
18 7619193325238
19 48430121151156
20 309011352878208
21 1978450305442086
22 12706836843595840