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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 21 |
| 4 | 153 |
| 5 | 1401 |
| 6 | 13083 |
| 7 | 130401 |
| 8 | 1334613 |
| 9 | 14048481 |
| 10 | 150675363 |
| 11 | 1642689501 |
| 12 | 18141639153 |
| 13 | 202569926121 |
| 14 | 2282923197003 |
| 15 | 25934267869401 |
| 16 | 296661689600733 |
| 17 | 3414170774033601 |
| 18 | 39503727765284163 |
| 19 | 459266320623014181 |
| 20 | 5362271816243579913 |
| 21 | 62850255058362431001 |
[1,3,21,153,1401,13083,130401,1334613,14048481, 150675363,1642689501,18141639153,202569926121, 2282923197003,25934267869401,296661689600733, 3414170774033601,39503727765284163, 459266320623014181,5362271816243579913, 62850255058362431001] |