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| n | a(n) |
|---|---|
| 1 | 8 |
| 2 | 128 |
| 3 | 630 |
| 4 | 4742 |
| 5 | 30116 |
| 6 | 204216 |
| 7 | 1349732 |
| 8 | 9010526 |
| 9 | 59917746 |
| 10 | 399048464 |
| 11 | 2656049918 |
| 12 | 17682689820 |
| 13 | 117712030990 |
| 14 | 783626030284 |
| 15 | 5216639296472 |
| 16 | 34727628846946 |
| 17 | 231184402116402 |
| 18 | 1539013000632024 |
| 19 | 10245328946153388 |
[8,128,630,4742,30116,204216,1349732,9010526, 59917746,399048464,2656049918,17682689820, 117712030990,783626030284,5216639296472, 34727628846946,231184402116402,1539013000632024, 10245328946153388] |