The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 4 | 1 |
| 5 | 30 |
| 6 | 630 |
| 7 | 11480 |
| 8 | 194580 |
| 9 | 3162510 |
| 10 | 50063860 |
| 11 | 778789440 |
| 12 | 11969016345 |
| 13 | 182364632450 |
| 14 | 2761025887620 |
| 15 | 41604694413840 |
| 16 | 624668654531480 |
| 17 | 9353014406656200 |
| 18 | 139737927523546800 |
| 19 | 2084196562669889040 |
[1,30,630,11480,194580,3162510,50063860,778789440, 11969016345,182364632450,2761025887620, 41604694413840,624668654531480,9353014406656200, 139737927523546800,2084196562669889040] |