| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 37 |
| 4 | 600 |
| 5 | 15229 |
| 6 | 554868 |
| 7 | 27444786 |
| 8 | 1770376080 |
| 9 | 144306428161 |
| 10 | 14507072762052 |
| 11 | 1762845211827574 |
| 12 | 254794661274061848 |
| 13 | 43191427238728121445 |
| 14 | 8488249087135630544628 |
| 15 | 1914196040519793284483542 |
| 16 | 491024013925643339847990144 |
| 17 | 142153433027873627036756565313 |
[1,1,4,37,600,15229,554868,27444786,1770376080, 144306428161,14507072762052,1762845211827574, 254794661274061848,43191427238728121445, 8488249087135630544628,1914196040519793284483542, 491024013925643339847990144, 142153433027873627036756565313] |