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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 15 |
| 4 | 54 |
| 5 | 193 |
| 6 | 708 |
| 7 | 2627 |
| 8 | 9846 |
| 9 | 37178 |
| 10 | 141223 |
| 11 | 539047 |
| 12 | 2065813 |
| 13 | 7943706 |
| 14 | 30634329 |
| 15 | 118433821 |
| 16 | 458867295 |
| 17 | 1781267606 |
| 18 | 6926405025 |
| 19 | 26973935420 |
| 20 | 105189301334 |
| 21 | 410707352869 |
| 22 | 1605379739149 |
| 23 | 6281519778025 |
| 24 | 24601184635436 |
[1,1,5,15,54,193,708,2627,9846,37178,141223, 539047,2065813,7943706,30634329,118433821, 458867295,1781267606,6926405025,26973935420, 105189301334,410707352869,1605379739149, 6281519778025,24601184635436] |