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| n | a(n) |
|---|---|
| 0 | 21 |
| 1 | 285 |
| 2 | 1365 |
| 3 | 4221 |
| 4 | 10197 |
| 5 | 21021 |
| 6 | 38805 |
| 7 | 66045 |
| 8 | 105621 |
| 9 | 160797 |
| 10 | 235221 |
| 11 | 332925 |
| 12 | 458325 |
| 13 | 616221 |
| 14 | 811797 |
| 15 | 1050621 |
| 16 | 1338645 |
| 17 | 1682205 |
| 18 | 2088021 |
| 19 | 2563197 |
| 20 | 3115221 |
| 21 | 3751965 |
| 22 | 4481685 |
| 23 | 5313021 |
| 24 | 6254997 |
| 25 | 7317021 |
| 26 | 8508885 |
| 27 | 9840765 |
| 28 | 11323221 |
[21,285,1365,4221,10197,21021,38805,66045,105621, 160797,235221,332925,458325,616221,811797,1050621, 1338645,1682205,2088021,2563197,3115221,3751965, 4481685,5313021,6254997,7317021,8508885,9840765, 11323221] |