n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 1 |
3 | 1 |
4 | 2 |
5 | 5 |
6 | 15 |
7 | 53 |
8 | 222 |
9 | 1078 |
10 | 5994 |
11 | 37622 |
12 | 262776 |
13 | 2018305 |
14 | 16873364 |
15 | 152233518 |
16 | 1471613387 |
17 | 15150569446 |
18 | 165269824761 |
19 | 1901910625578 |
20 | 23003059864006 |
[1,1,1,1,2,5,15,53,222,1078,5994,37622,262776, 2018305,16873364,152233518,1471613387,15150569446, 165269824761,1901910625578,23003059864006] |