| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 9 |
| 3 | 43 |
| 4 | 206 |
| 5 | 987 |
| 6 | 4729 |
| 7 | 22658 |
| 8 | 108561 |
| 9 | 520147 |
| 10 | 2492174 |
| 11 | 11940723 |
| 12 | 57211441 |
| 13 | 274116482 |
| 14 | 1313370969 |
| 15 | 6292738363 |
| 16 | 30150320846 |
| 17 | 144458865867 |
| 18 | 692144008489 |
| 19 | 3316261176578 |
| 20 | 15889161874401 |
| 21 | 76129548195427 |
| 22 | 364758579102734 |
| 23 | 1747663347318243 |
[1,2,9,43,206,987,4729,22658,108561,520147, 2492174,11940723,57211441,274116482,1313370969, 6292738363,30150320846,144458865867,692144008489, 3316261176578,15889161874401,76129548195427, 364758579102734,1747663347318243] |