n | a(n) |
---|---|
0 | 1 |
1 | 2 |
2 | 1 |
3 | 2 |
4 | 6 |
5 | 20 |
6 | 69 |
7 | 270 |
8 | 1026 |
9 | 4120 |
10 | 16794 |
11 | 70230 |
12 | 298306 |
13 | 1288912 |
14 | 5642559 |
15 | 25007756 |
16 | 111998920 |
17 | 506348902 |
18 | 2308338456 |
19 | 10602357346 |
20 | 49026021552 |
21 | 228085486580 |
22 | 1067020210339 |
23 | 5016982766202 |
24 | 23698640081356 |
25 | 112422573858292 |
26 | 535414026652828 |
27 | 2559204304109868 |
[1,2,1,2,6,20,69,270,1026,4120,16794,70230,298306, 1288912,5642559,25007756,111998920,506348902, 2308338456,10602357346,49026021552,228085486580, 1067020210339,5016982766202,23698640081356, 112422573858292,535414026652828,2559204304109868] |