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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 27 |
| 3 | 338 |
| 4 | 2835 |
| 5 | 18566 |
| 6 | 101955 |
| 7 | 490253 |
| 8 | 2121679 |
| 9 | 8424520 |
| 10 | 31120519 |
| 11 | 108082568 |
| 12 | 355805844 |
| 13 | 1117485594 |
| 14 | 3366122862 |
| 15 | 9767102571 |
| 16 | 27398599802 |
| 17 | 74534162438 |
| 18 | 197147428426 |
| 19 | 508187725366 |
| 20 | 1279132093597 |
| 21 | 3149343999710 |
| 22 | 7596355910693 |
| 23 | 17974782074306 |
| 24 | 41775768918777 |
[1,27,338,2835,18566,101955,490253,2121679, 8424520,31120519,108082568,355805844,1117485594, 3366122862,9767102571,27398599802,74534162438, 197147428426,508187725366,1279132093597, 3149343999710,7596355910693,17974782074306, 41775768918777] |