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| n | a(n) |
|---|---|
| 1 | 81 |
| 2 | 287 |
| 3 | 1069 |
| 4 | 4131 |
| 5 | 16153 |
| 6 | 63867 |
| 7 | 253269 |
| 8 | 1008347 |
| 9 | 4017129 |
| 10 | 16029051 |
| 11 | 63964053 |
| 12 | 255428971 |
| 13 | 1020001673 |
| 14 | 4074620555 |
| 15 | 16277074485 |
| 16 | 65036521755 |
| 17 | 259868094441 |
| 18 | 1038512291675 |
| 19 | 4150437015637 |
| 20 | 16589196684619 |
| 21 | 66311024500553 |
[81,287,1069,4131,16153,63867,253269,1008347, 4017129,16029051,63964053,255428971,1020001673, 4074620555,16277074485,65036521755,259868094441, 1038512291675,4150437015637,16589196684619, 66311024500553] |