| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 21 |
| 3 | 65 |
| 4 | 245 |
| 5 | 1060 |
| 6 | 4744 |
| 7 | 19397 |
| 8 | 81885 |
| 9 | 331324 |
| 10 | 1324884 |
| 11 | 5274136 |
| 12 | 21037000 |
| 13 | 84020280 |
| 14 | 335815688 |
| 15 | 1342723056 |
[1,5,21,65,245,1060,4744,19397,81885,331324, 1324884,5274136,21037000,84020280,335815688, 1342723056] |