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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 7 |
| 2 | 53 |
| 3 | 431 |
| 4 | 3741 |
| 5 | 34471 |
| 6 | 335621 |
| 7 | 3438943 |
| 8 | 36954285 |
| 9 | 415187415 |
| 10 | 4864054165 |
| 11 | 59278367247 |
| 12 | 749926582717 |
| 13 | 9829744447495 |
| 14 | 133267495918885 |
| 15 | 1865916660838847 |
| 16 | 26942271261464525 |
| 17 | 400673643394972983 |
| 18 | 6129834703935247285 |
| 19 | 96368617886967750767 |
| 20 | 1555302323744129219293 |
[1,7,53,431,3741,34471,335621,3438943,36954285, 415187415,4864054165,59278367247,749926582717, 9829744447495,133267495918885,1865916660838847, 26942271261464525,400673643394972983, 6129834703935247285,96368617886967750767, 1555302323744129219293] |