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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 18 |
| 3 | 431 |
| 4 | 422207 |
| 5 | 250930742830 |
| 6 | 127624025845850320931524 |
| 7 | 20440779710397374804994946272458531398862740458 |
| 8 | 1219942980264902943773487885079394593557022501247782054380175375253125647677550932401339826178 |
[3,18,431,422207,250930742830, 127624025845850320931524, 20440779710397374804994946272458531398862740458, 12199429802649029437734878850793945935570225012477\ 82054380175375253125647677550932401339826178] |