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| n | a(n) |
|---|---|
| 0 | 4 |
| 1 | 33 |
| 2 | 268 |
| 3 | 2177 |
| 4 | 17684 |
| 5 | 143649 |
| 6 | 1166876 |
| 7 | 9478657 |
| 8 | 76996132 |
| 9 | 625447713 |
| 10 | 5080577836 |
| 11 | 41270070401 |
| 12 | 335241141044 |
| 13 | 2723199198753 |
| 14 | 22120834731068 |
| 15 | 179689877047297 |
| 16 | 1459639851109444 |
| 17 | 11856808685922849 |
| 18 | 96314109338492236 |
[4,33,268,2177,17684,143649,1166876,9478657, 76996132,625447713,5080577836,41270070401, 335241141044,2723199198753,22120834731068, 179689877047297,1459639851109444, 11856808685922849,96314109338492236] |