| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 12 |
| 3 | 18 |
| 4 | 220 |
| 5 | 396 |
| 6 | 17296 |
| 7 | 24016 |
| 8 | 287532 |
| 9 | 4661056 |
| 10 | 64288512 |
| 11 | 334144656 |
| 12 | 358585488 |
| 13 | 555192576 |
| 14 | 568719616 |
| 15 | 2172649216 |
| 16 | 2451538112 |
| 17 | 2645953344 |
| 18 | 2955423888 |
| 19 | 6704333824 |
| 20 | 26996772032 |
| 21 | 88734733632 |
| 22 | 147861504000 |
| 23 | 311063879024 |
| 24 | 371226582848 |
| 25 | 429391876096 |
[1,12,18,220,396,17296,24016,287532,4661056, 64288512,334144656,358585488,555192576,568719616, 2172649216,2451538112,2645953344,2955423888, 6704333824,26996772032,88734733632,147861504000, 311063879024,371226582848,429391876096] |