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| n | a(n) |
|---|---|
| 1 | 15 |
| 2 | 144 |
| 3 | 1137 |
| 4 | 4584 |
| 5 | 15843 |
| 6 | 40392 |
| 7 | 95109 |
| 8 | 189936 |
| 9 | 362487 |
| 10 | 625440 |
| 11 | 1048665 |
| 12 | 1643544 |
| 13 | 2526027 |
| 14 | 3699864 |
| 15 | 5343213 |
| 16 | 7443552 |
| 17 | 10259679 |
| 18 | 13751856 |
| 19 | 18280257 |
| 20 | 23764680 |
| 21 | 30689715 |
| 22 | 38919144 |
| 23 | 49087317 |
| 24 | 60984144 |
| 25 | 75421383 |
| 26 | 92094912 |
| 27 | 112023849 |
[15,144,1137,4584,15843,40392,95109,189936,362487, 625440,1048665,1643544,2526027,3699864,5343213, 7443552,10259679,13751856,18280257,23764680, 30689715,38919144,49087317,60984144,75421383, 92094912,112023849] |