n | a(n) |
---|---|
1 | 1 |
2 | 3 |
3 | 12 |
4 | 40 |
5 | 130 |
6 | 404 |
7 | 1227 |
8 | 3653 |
9 | 10720 |
10 | 31090 |
11 | 89316 |
12 | 254568 |
13 | 720757 |
14 | 2029095 |
15 | 5684340 |
16 | 15855964 |
17 | 44061862 |
18 | 122032508 |
19 | 336966015 |
20 | 927953705 |
21 | 2549229256 |
22 | 6987648358 |
23 | 19115124552 |
24 | 52194037200 |
25 | 142274514025 |
26 | 387215773899 |
[1,3,12,40,130,404,1227,3653,10720,31090,89316, 254568,720757,2029095,5684340,15855964,44061862, 122032508,336966015,927953705,2549229256, 6987648358,19115124552,52194037200,142274514025, 387215773899] |