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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 9 |
| 3 | 45 |
| 4 | 144 |
| 5 | 512 |
| 6 | 1936 |
| 7 | 7381 |
| 8 | 27225 |
| 9 | 101250 |
| 10 | 378225 |
| 11 | 1413721 |
| 12 | 5271616 |
| 13 | 19668992 |
| 14 | 73410624 |
| 15 | 274002345 |
| 16 | 1022528529 |
| 17 | 3816059522 |
| 18 | 14241796921 |
| 19 | 53151529861 |
| 20 | 198363344400 |
| 21 | 740301120000 |
| 22 | 2762842352400 |
| 23 | 10311073884541 |
| 24 | 38481439562281 |
[2,9,45,144,512,1936,7381,27225,101250,378225, 1413721,5271616,19668992,73410624,274002345, 1022528529,3816059522,14241796921,53151529861, 198363344400,740301120000,2762842352400, 10311073884541,38481439562281] |