The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 6 | 15 |
| 7 | 315 |
| 8 | 4480 |
| 9 | 56672 |
| 10 | 703430 |
| 11 | 8941790 |
| 12 | 118685336 |
| 13 | 1658897240 |
| 14 | 24494859389 |
| 15 | 382301179169 |
| 16 | 6302039460704 |
| 17 | 109568927676192 |
| 18 | 2005758201911884 |
| 19 | 38588518087076860 |
| 20 | 778794884783432176 |
| 21 | 16458419973887378416 |
| 22 | 363578176719852275467 |
| 23 | 8381709371219530604071 |
[15,315,4480,56672,703430,8941790,118685336, 1658897240,24494859389,382301179169,6302039460704, 109568927676192,2005758201911884, 38588518087076860,778794884783432176, 16458419973887378416,363578176719852275467, 8381709371219530604071] |