n | a(n) |
---|---|
1 | 0 |
2 | 0 |
3 | 0 |
4 | 1 |
5 | 2 |
6 | 12 |
7 | 53 |
8 | 250 |
9 | 1115 |
10 | 5012 |
11 | 22032 |
12 | 96746 |
13 | 422732 |
14 | 1848128 |
15 | 8088090 |
16 | 35498533 |
17 | 156328706 |
18 | 691192578 |
19 | 3068780449 |
20 | 13683070474 |
21 | 61267204610 |
22 | 275455737555 |
23 | 1243320744572 |
24 | 5633022679582 |
25 | 25611815936218 |
26 | 116840427373176 |
27 | 534705818846660 |
28 | 2454282243059471 |
[0,0,0,1,2,12,53,250,1115,5012,22032,96746,422732, 1848128,8088090,35498533,156328706,691192578, 3068780449,13683070474,61267204610,275455737555, 1243320744572,5633022679582,25611815936218, 116840427373176,534705818846660,2454282243059471] |