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| n | a(n) |
|---|---|
| 1 | 21 |
| 2 | 77 |
| 3 | 221 |
| 4 | 437 |
| 5 | 1517 |
| 6 | 2021 |
| 7 | 4757 |
| 8 | 6557 |
| 9 | 9797 |
| 10 | 11021 |
| 11 | 12317 |
| 12 | 16637 |
| 13 | 27221 |
| 14 | 38021 |
| 15 | 50621 |
| 16 | 53357 |
| 17 | 77837 |
| 18 | 95477 |
| 19 | 99221 |
| 20 | 123197 |
| 21 | 145157 |
| 22 | 159197 |
| 23 | 194477 |
| 24 | 210677 |
| 25 | 216221 |
| 26 | 239117 |
| 27 | 250997 |
| 28 | 378221 |
| 29 | 416021 |
| 30 | 455621 |
| 31 | 549077 |
| 32 | 576077 |
| 33 | 594437 |
| 34 | 680621 |
[21,77,221,437,1517,2021,4757,6557,9797,11021, 12317,16637,27221,38021,50621,53357,77837,95477, 99221,123197,145157,159197,194477,210677,216221, 239117,250997,378221,416021,455621,549077,576077, 594437,680621] |