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| n | a(n) |
|---|---|
| 1 | 7 |
| 2 | 28 |
| 3 | 132 |
| 4 | 666 |
| 5 | 3234 |
| 6 | 17514 |
| 7 | 100674 |
| 8 | 501228 |
| 9 | 2062662 |
| 10 | 211097334 |
| 11 | 2597411082 |
| 12 | 34473310284 |
| 13 | 214852200444 |
| 14 | 394471192794 |
[7,28,132,666,3234,17514,100674,501228,2062662, 211097334,2597411082,34473310284,214852200444, 394471192794] |