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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 13 |
| 2 | 90 |
| 3 | 442 |
| 4 | 1728 |
| 5 | 5720 |
| 6 | 16653 |
| 7 | 43745 |
| 8 | 105586 |
| 9 | 237354 |
| 10 | 502113 |
| 11 | 1007773 |
| 12 | 1931631 |
| 13 | 3554746 |
| 14 | 6308706 |
| 15 | 10837593 |
| 16 | 18078112 |
| 17 | 29360890 |
| 18 | 46535840 |
| 19 | 72124195 |
| 20 | 109499325 |
| 21 | 163097740 |
| 22 | 238660747 |
| 23 | 343506072 |
| 24 | 486827392 |
| 25 | 680018170 |
| 26 | 937014482 |
| 27 | 1274649714 |
[1,13,90,442,1728,5720,16653,43745,105586,237354, 502113,1007773,1931631,3554746,6308706,10837593, 18078112,29360890,46535840,72124195,109499325, 163097740,238660747,343506072,486827392,680018170, 937014482,1274649714] |