n | a(n) |
---|---|
0 | 1 |
1 | 0 |
2 | 3 |
3 | 6 |
4 | 21 |
5 | 60 |
6 | 183 |
7 | 546 |
8 | 1641 |
9 | 4920 |
10 | 14763 |
11 | 44286 |
12 | 132861 |
13 | 398580 |
14 | 1195743 |
15 | 3587226 |
16 | 10761681 |
17 | 32285040 |
18 | 96855123 |
19 | 290565366 |
20 | 871696101 |
21 | 2615088300 |
22 | 7845264903 |
23 | 23535794706 |
24 | 70607384121 |
25 | 211822152360 |
26 | 635466457083 |
[1,0,3,6,21,60,183,546,1641,4920,14763,44286, 132861,398580,1195743,3587226,10761681,32285040, 96855123,290565366,871696101,2615088300, 7845264903,23535794706,70607384121,211822152360, 635466457083] |