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| n | a(n) |
|---|---|
| 1 | 63 |
| 2 | 364 |
| 3 | 3906 |
| 4 | 19608 |
| 5 | 177156 |
| 6 | 402234 |
| 7 | 1508598 |
| 8 | 2613660 |
| 9 | 6728904 |
| 10 | 21243690 |
| 11 | 29583456 |
| 12 | 71270178 |
| 13 | 118752606 |
| 14 | 150508644 |
| 15 | 234330768 |
| 16 | 426237714 |
| 17 | 727250580 |
| 18 | 858672906 |
| 19 | 1370581548 |
| 20 | 1830004056 |
| 21 | 2101864254 |
| 22 | 3116505840 |
| 23 | 3987077724 |
[63,364,3906,19608,177156,402234,1508598,2613660, 6728904,21243690,29583456,71270178,118752606, 150508644,234330768,426237714,727250580,858672906, 1370581548,1830004056,2101864254,3116505840, 3987077724] |