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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 66 |
| 3 | 362 |
| 4 | 1736 |
| 5 | 5621 |
| 6 | 18509 |
| 7 | 48341 |
| 8 | 125429 |
| 9 | 288869 |
| 10 | 645578 |
| 11 | 1338336 |
| 12 | 2704063 |
| 13 | 5170784 |
| 14 | 9654395 |
| 15 | 17329591 |
| 16 | 30416751 |
| 17 | 51788999 |
| 18 | 86492839 |
[2,66,362,1736,5621,18509,48341,125429,288869, 645578,1338336,2704063,5170784,9654395,17329591, 30416751,51788999,86492839] |