# A097833 (b-file synthesized from sequence entry)
0 1
1 21
2 420
3 8380
4 167181
5 3335241
6 66537640
7 1327417560
8 26481813561
9 528308853661
10 10539695259660
11 210265596339540
12 4194772231531141
13 83685179034283281
14 1669508808454134480
15 33306490990048406320