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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 22 |
| 3 | 211 |
| 4 | 2306 |
| 5 | 27230 |
| 6 | 338444 |
| 7 | 4362627 |
| 8 | 57788170 |
| 9 | 781825066 |
| 10 | 10757497972 |
| 11 | 150073096238 |
| 12 | 2117778107732 |
| 13 | 30176799215196 |
| 14 | 433586825237912 |
| 15 | 6274885068167651 |
| 16 | 91383942213277530 |
| 17 | 1338275570267001458 |
| 18 | 19695358741104824036 |
| 19 | 291137841642777382330 |
| 20 | 4320734864185863437820 |
[1,3,22,211,2306,27230,338444,4362627,57788170, 781825066,10757497972,150073096238,2117778107732, 30176799215196,433586825237912,6274885068167651, 91383942213277530,1338275570267001458, 19695358741104824036,291137841642777382330, 4320734864185863437820] |