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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 9 |
| 3 | 36 |
| 4 | 169 |
| 5 | 576 |
| 6 | 2304 |
| 7 | 7396 |
| 8 | 25600 |
| 9 | 79524 |
| 10 | 250000 |
| 11 | 737881 |
| 12 | 2187441 |
| 13 | 6175225 |
| 14 | 17363889 |
| 15 | 47320641 |
| 16 | 127622209 |
| 17 | 336135556 |
| 18 | 876219201 |
| 19 | 2240128900 |
| 20 | 5666777284 |
| 21 | 14112014436 |
| 22 | 34772925625 |
| 23 | 84554753089 |
| 24 | 203576025636 |
| 25 | 484461937089 |
| 26 | 1142215875025 |
| 27 | 2665572144964 |
| 28 | 6166451098756 |
[1,1,9,36,169,576,2304,7396,25600,79524,250000, 737881,2187441,6175225,17363889,47320641, 127622209,336135556,876219201,2240128900, 5666777284,14112014436,34772925625,84554753089, 203576025636,484461937089,1142215875025, 2665572144964,6166451098756] |