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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 7 |
| 3 | 44 |
| 4 | 268 |
| 5 | 1609 |
| 6 | 9583 |
| 7 | 56792 |
| 8 | 335448 |
| 9 | 1976689 |
| 10 | 11627735 |
| 11 | 68308580 |
| 12 | 400870468 |
| 13 | 2350563097 |
| 14 | 13773547487 |
| 15 | 80663415344 |
| 16 | 472175746096 |
| 17 | 2762854639585 |
| 18 | 16160861104423 |
| 19 | 94502471413916 |
| 20 | 552472329537660 |
[1,7,44,268,1609,9583,56792,335448,1976689, 11627735,68308580,400870468,2350563097, 13773547487,80663415344,472175746096, 2762854639585,16160861104423,94502471413916, 552472329537660] |