n | a(n) |
---|---|
1 | 1 |
2 | 1 |
3 | 1 |
4 | 2 |
5 | 4 |
6 | 10 |
7 | 28 |
8 | 77 |
9 | 221 |
10 | 650 |
11 | 1951 |
12 | 5920 |
13 | 18211 |
14 | 56509 |
15 | 176919 |
16 | 557786 |
17 | 1769966 |
18 | 5647568 |
19 | 18110734 |
20 | 58335561 |
21 | 188658338 |
22 | 612337013 |
23 | 1994058293 |
24 | 6513153445 |
25 | 21332562178 |
26 | 70048092196 |
27 | 230550762108 |
28 | 760462920317 |
[1,1,1,2,4,10,28,77,221,650,1951,5920,18211,56509, 176919,557786,1769966,5647568,18110734,58335561, 188658338,612337013,1994058293,6513153445, 21332562178,70048092196,230550762108,760462920317] |