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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 13 |
| 3 | 172 |
| 4 | 2356 |
| 5 | 32661 |
| 6 | 454329 |
| 7 | 6325816 |
| 8 | 88099144 |
| 9 | 1227032521 |
| 10 | 17090245381 |
| 11 | 238035989412 |
| 12 | 3315412063548 |
| 13 | 46177727142301 |
| 14 | 643172746439665 |
| 15 | 8958240642814960 |
| 16 | 124772195953666576 |
| 17 | 1737852501591502353 |
| 18 | 24205162822158610557 |
| 19 | 337134426993071036956 |
| 20 | 4695676815022772628676 |
| 21 | 65402340983109050660389 |
[1,13,172,2356,32661,454329,6325816,88099144, 1227032521,17090245381,238035989412,3315412063548, 46177727142301,643172746439665,8958240642814960, 124772195953666576,1737852501591502353, 24205162822158610557,337134426993071036956, 4695676815022772628676,65402340983109050660389] |