| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 8 |
| 4 | 21 |
| 5 | 68 |
| 6 | 214 |
| 7 | 677 |
| 8 | 2273 |
| 9 | 7647 |
| 10 | 25918 |
| 11 | 89348 |
| 12 | 311027 |
| 13 | 1088056 |
| 14 | 3829653 |
| 15 | 13588462 |
| 16 | 48394968 |
| 17 | 172944341 |
| 18 | 621204971 |
| 19 | 2238314211 |
| 20 | 8085624821 |
| 21 | 29299373131 |
| 22 | 106444414667 |
| 23 | 387514343973 |
| 24 | 1413668394353 |
| 25 | 5167606834130 |
| 26 | 18922163532610 |
| 27 | 69393623143969 |
| 28 | 254887907279952 |
| 29 | 937530482411295 |
| 30 | 3452720455224744 |
[1,1,3,8,21,68,214,677,2273,7647,25918,89348, 311027,1088056,3829653,13588462,48394968, 172944341,621204971,2238314211,8085624821, 29299373131,106444414667,387514343973, 1413668394353,5167606834130,18922163532610, 69393623143969,254887907279952,937530482411295, 3452720455224744] |