# A003268 (b-file synthesized from sequence entry)
0 1
1 2
2 6
3 15
4 60
5 260
6 1820
7 12376
8 136136
9 1514513
10 27261234
11 488605194
12 14169550626
13 411591708660
14 19344810307020
15 908637119420910
16 69056421075989160
17 5249543573067466872
18 645693859487298425256
19 79413089729752455762384
20 15803204856220738696714416