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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 12 |
| 3 | 61 |
| 4 | 457 |
| 5 | 3411 |
| 6 | 31487 |
| 7 | 317655 |
| 8 | 3161392 |
| 9 | 31436637 |
| 10 | 315944445 |
| 11 | 3182997999 |
| 12 | 32059374557 |
| 13 | 323386403994 |
| 14 | 3267568146811 |
| 15 | 33053624461081 |
| 16 | 334704837151091 |
| 17 | 3392894959638835 |
| 18 | 34428005433287948 |
| 19 | 349661755820884825 |
[4,12,61,457,3411,31487,317655,3161392,31436637, 315944445,3182997999,32059374557,323386403994, 3267568146811,33053624461081,334704837151091, 3392894959638835,34428005433287948, 349661755820884825] |