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| n | a(n) |
|---|---|
| 1 | 81 |
| 2 | 308 |
| 3 | 1144 |
| 4 | 4272 |
| 5 | 16280 |
| 6 | 61152 |
| 7 | 231680 |
| 8 | 869120 |
| 9 | 3299584 |
| 10 | 12382208 |
| 11 | 46966784 |
| 12 | 176229376 |
| 13 | 668720640 |
| 14 | 2509305856 |
| 15 | 9520095232 |
| 16 | 35722403840 |
| 17 | 135538946048 |
| 18 | 508589948928 |
| 19 | 1929634152448 |
| 20 | 7240635777024 |
| 21 | 27472062906368 |
| 22 | 103084621299712 |
[81,308,1144,4272,16280,61152,231680,869120, 3299584,12382208,46966784,176229376,668720640, 2509305856,9520095232,35722403840,135538946048, 508589948928,1929634152448,7240635777024, 27472062906368,103084621299712] |