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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 12 |
| 4 | 54 |
| 5 | 259 |
| 6 | 1293 |
| 7 | 6634 |
| 8 | 34716 |
| 9 | 184389 |
| 10 | 990711 |
| 11 | 5372088 |
| 12 | 29347794 |
| 13 | 161317671 |
| 14 | 891313569 |
| 15 | 4946324886 |
| 16 | 27552980088 |
| 17 | 153982124809 |
| 18 | 862997075691 |
| 19 | 4848839608228 |
| 20 | 27304369787694 |
| 21 | 154059320699211 |
| 22 | 870796075968693 |
| 23 | 4929937918315522 |
| 24 | 27950989413184404 |
[1,1,3,12,54,259,1293,6634,34716,184389,990711, 5372088,29347794,161317671,891313569,4946324886, 27552980088,153982124809,862997075691, 4848839608228,27304369787694,154059320699211, 870796075968693,4929937918315522, 27950989413184404] |