n | a(n) |
---|---|
1 | 1 |
2 | 0 |
3 | 2 |
4 | 3 |
5 | 9 |
6 | 23 |
7 | 73 |
8 | 229 |
9 | 796 |
10 | 2891 |
11 | 11118 |
12 | 44695 |
13 | 187825 |
14 | 820320 |
15 | 3716501 |
16 | 17413308 |
17 | 84209071 |
18 | 419461933 |
19 | 2148673503 |
20 | 11301526295 |
21 | 60956491070 |
22 | 336744177291 |
23 | 1903317319015 |
24 | 10995856040076 |
25 | 64873456288903 |
26 | 390544727861462 |
27 | 2397255454976268 |
28 | 14993279955728851 |
[1,0,2,3,9,23,73,229,796,2891,11118,44695,187825, 820320,3716501,17413308,84209071,419461933, 2148673503,11301526295,60956491070,336744177291, 1903317319015,10995856040076,64873456288903, 390544727861462,2397255454976268, 14993279955728851] |