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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 15 |
| 4 | 83 |
| 5 | 486 |
| 6 | 2967 |
| 7 | 18748 |
| 8 | 121725 |
| 9 | 807381 |
| 10 | 5447203 |
| 11 | 37264974 |
| 12 | 257896500 |
| 13 | 1802312605 |
| 14 | 12701190885 |
| 15 | 90157130289 |
| 16 | 644022007040 |
| 17 | 4626159163233 |
[1,3,15,83,486,2967,18748,121725,807381,5447203, 37264974,257896500,1802312605,12701190885, 90157130289,644022007040,4626159163233] |