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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 19 |
| 2 | 230 |
| 3 | 2270 |
| 4 | 19971 |
| 5 | 163569 |
| 6 | 1278040 |
| 7 | 9670540 |
| 8 | 71557541 |
| 9 | 521211119 |
| 10 | 3754036650 |
| 11 | 26822296410 |
| 12 | 190541788711 |
| 13 | 1347984742669 |
| 14 | 9507913700060 |
| 15 | 66919750327880 |
| 16 | 470277075161481 |
| 17 | 3301201972518219 |
| 18 | 23154999755212270 |
| 19 | 162319024049252950 |
| 20 | 1137407684744763851 |
[1,19,230,2270,19971,163569,1278040,9670540, 71557541,521211119,3754036650,26822296410, 190541788711,1347984742669,9507913700060, 66919750327880,470277075161481,3301201972518219, 23154999755212270,162319024049252950, 1137407684744763851] |