| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 24 |
| 2 | 552 |
| 3 | 12696 |
| 4 | 292008 |
| 5 | 6716184 |
| 6 | 154472232 |
| 7 | 3552861336 |
| 8 | 81715810728 |
| 9 | 1879463646744 |
| 10 | 43227663875112 |
| 11 | 994236269127576 |
| 12 | 22867434189934248 |
| 13 | 525950986368487704 |
| 14 | 12096872686475217192 |
| 15 | 278228071788929995416 |
[1,24,552,12696,292008,6716184,154472232, 3552861336,81715810728,1879463646744, 43227663875112,994236269127576,22867434189934248, 525950986368487704,12096872686475217192, 278228071788929995416] |