| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 16 |
| 2 | 287 |
| 3 | 5954 |
| 4 | 142590 |
| 5 | 3900480 |
| 6 | 120466080 |
| 7 | 4156079760 |
| 8 | 158664456720 |
| 9 | 6647965632000 |
| 10 | 303540020784000 |
| 11 | 15009431909472000 |
| 12 | 799414492260384000 |
| 13 | 45641465547245568000 |
| 14 | 2781538377619921920000 |
| 15 | 180263592116387619840000 |
| 16 | 12381113998069012804608000 |
[1,16,287,5954,142590,3900480,120466080, 4156079760,158664456720,6647965632000, 303540020784000,15009431909472000, 799414492260384000,45641465547245568000, 2781538377619921920000,180263592116387619840000, 12381113998069012804608000] |