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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 42 |
| 4 | 471 |
| 5 | 6435 |
| 6 | 102232 |
| 7 | 1837630 |
| 8 | 36719439 |
| 9 | 805716679 |
| 10 | 19239923577 |
| 11 | 496514053880 |
| 12 | 13769677836500 |
| 13 | 408449335836132 |
| 14 | 12906850662570996 |
| 15 | 432942515731367894 |
| 16 | 15367227978734187567 |
| 17 | 575544844737119275935 |
| 18 | 22685977410186834271463 |
| 19 | 938867118118688412116554 |
[1,1,5,42,471,6435,102232,1837630,36719439, 805716679,19239923577,496514053880,13769677836500, 408449335836132,12906850662570996, 432942515731367894,15367227978734187567, 575544844737119275935,22685977410186834271463, 938867118118688412116554] |