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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 30 |
| 3 | 181 |
| 4 | 874 |
| 5 | 3711 |
| 6 | 14524 |
| 7 | 53736 |
| 8 | 190782 |
| 9 | 656350 |
| 10 | 2202647 |
| 11 | 7244772 |
| 12 | 23436690 |
| 13 | 74767864 |
| 14 | 235710440 |
| 15 | 735528909 |
| 16 | 2274844294 |
| 17 | 6980781346 |
| 18 | 21273830001 |
| 19 | 64432110648 |
| 20 | 194066078164 |
| 21 | 581597738908 |
| 22 | 1735097817528 |
| 23 | 5155001023066 |
[3,30,181,874,3711,14524,53736,190782,656350, 2202647,7244772,23436690,74767864,235710440, 735528909,2274844294,6980781346,21273830001, 64432110648,194066078164,581597738908, 1735097817528,5155001023066] |