| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 12 |
| 3 | 52 |
| 4 | 235 |
| 5 | 1101 |
| 6 | 5220 |
| 7 | 25095 |
| 8 | 121545 |
| 9 | 592284 |
| 10 | 2899874 |
| 11 | 14245601 |
| 12 | 70184982 |
| 13 | 346528860 |
| 14 | 1714063397 |
| 15 | 8490860344 |
| 16 | 42111682813 |
| 17 | 209073230631 |
| 18 | 1038876078407 |
| 19 | 5165898092581 |
| 20 | 25703761512770 |
| 21 | 127961411281276 |
| 22 | 637325546777479 |
| 23 | 3175535870819601 |
| 24 | 15827934678897576 |
| 25 | 78915817742970026 |
[1,3,12,52,235,1101,5220,25095,121545,592284, 2899874,14245601,70184982,346528860,1714063397, 8490860344,42111682813,209073230631,1038876078407, 5165898092581,25703761512770,127961411281276, 637325546777479,3175535870819601, 15827934678897576,78915817742970026] |