n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 1 |
3 | 3 |
4 | 7 |
5 | 18 |
6 | 51 |
7 | 155 |
8 | 486 |
9 | 1555 |
10 | 5095 |
11 | 17038 |
12 | 57801 |
13 | 198471 |
14 | 689039 |
15 | 2415043 |
16 | 8534022 |
17 | 30375188 |
18 | 108815273 |
19 | 392076629 |
20 | 1420064031 |
21 | 5167575997 |
22 | 18885299641 |
23 | 69287981666 |
24 | 255121926519 |
25 | 942474271999 |
26 | 3492314839349 |
27 | 12977225566680 |
28 | 48349025154154 |
[1,1,1,3,7,18,51,155,486,1555,5095,17038,57801, 198471,689039,2415043,8534022,30375188,108815273, 392076629,1420064031,5167575997,18885299641, 69287981666,255121926519,942474271999, 3492314839349,12977225566680,48349025154154] |