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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 6 |
| 5 | 26 |
| 6 | 96 |
| 7 | 210 |
| 8 | 1106 |
| 9 | 3759 |
| 10 | 12577 |
| 11 | 74072 |
| 12 | 423884 |
| 13 | 2333828 |
| 14 | 16736611 |
| 15 | 99838851 |
| 16 | 630091746 |
| 17 | 4525325020 |
| 18 | 38848875650 |
| 19 | 342245714017 |
| 20 | 3335164762941 |
| 21 | 31315463942337 |
| 22 | 241353231085002 |
| 23 | 2350106537365732 |
| 24 | 17903852593938447 |
| 25 | 158065352670318614 |
| 26 | 1815064841856534244 |
| 27 | 20577063085601738871 |
| 28 | 276081763499377227299 |
[1,2,3,6,26,96,210,1106,3759,12577,74072,423884, 2333828,16736611,99838851,630091746,4525325020, 38848875650,342245714017,3335164762941, 31315463942337,241353231085002,2350106537365732, 17903852593938447,158065352670318614, 1815064841856534244,20577063085601738871, 276081763499377227299] |