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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 18 |
| 3 | 51 |
| 4 | 189 |
| 5 | 630 |
| 6 | 2187 |
| 7 | 7473 |
| 8 | 25692 |
| 9 | 88119 |
| 10 | 302511 |
| 11 | 1038144 |
| 12 | 3563151 |
| 13 | 12228903 |
| 14 | 41971050 |
| 15 | 144048471 |
| 16 | 494389041 |
| 17 | 1696791534 |
| 18 | 5823557223 |
| 19 | 19987023645 |
| 20 | 68597444364 |
| 21 | 235433215419 |
| 22 | 808030095435 |
| 23 | 2773239244320 |
| 24 | 9518031521451 |
[3,18,51,189,630,2187,7473,25692,88119,302511, 1038144,3563151,12228903,41971050,144048471, 494389041,1696791534,5823557223,19987023645, 68597444364,235433215419,808030095435, 2773239244320,9518031521451] |