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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 7 |
| 3 | 43 |
| 4 | 280 |
| 5 | 1792 |
| 6 | 11586 |
| 7 | 74550 |
| 8 | 479892 |
| 9 | 3083640 |
| 10 | 19794678 |
| 11 | 126908502 |
| 12 | 812761299 |
| 13 | 5199586119 |
| 14 | 33230586285 |
| 15 | 212172173565 |
| 16 | 1353444677529 |
| 17 | 8626044781761 |
| 18 | 54931168743703 |
| 19 | 349524243121795 |
| 20 | 2222294161109422 |
| 21 | 14119034725444774 |
| 22 | 89639674321304392 |
| 23 | 568720801952770012 |
[1,1,7,43,280,1792,11586,74550,479892,3083640, 19794678,126908502,812761299,5199586119, 33230586285,212172173565,1353444677529, 8626044781761,54931168743703,349524243121795, 2222294161109422,14119034725444774, 89639674321304392,568720801952770012] |