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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 19 |
| 5 | 61 |
| 6 | 196 |
| 7 | 630 |
| 8 | 2024 |
| 9 | 6499 |
| 10 | 20860 |
| 11 | 66941 |
| 12 | 214797 |
| 13 | 689201 |
| 14 | 2211347 |
| 15 | 7095226 |
| 16 | 22765414 |
| 17 | 73044113 |
| 18 | 234366327 |
| 19 | 751978494 |
| 20 | 2412768983 |
| 21 | 7741517800 |
| 22 | 24839137696 |
| 23 | 79697907919 |
| 24 | 255715662623 |
[1,2,6,19,61,196,630,2024,6499,20860,66941,214797, 689201,2211347,7095226,22765414,73044113, 234366327,751978494,2412768983,7741517800, 24839137696,79697907919,255715662623] |