The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 3 | 1 |
| 4 | 23 |
| 5 | 230 |
| 6 | 1682 |
| 7 | 10543 |
| 8 | 60657 |
| 9 | 331612 |
| 10 | 1756340 |
| 11 | 9116141 |
| 12 | 46702427 |
| 13 | 237231970 |
| 14 | 1198382694 |
| 15 | 6031771195 |
| 16 | 30287995733 |
| 17 | 151856096504 |
| 18 | 760614930344 |
| 19 | 3807336276505 |
| 20 | 19050241098975 |
| 21 | 95294209168414 |
| 22 | 476607030432890 |
[1,23,230,1682,10543,60657,331612,1756340,9116141, 46702427,237231970,1198382694,6031771195, 30287995733,151856096504,760614930344, 3807336276505,19050241098975,95294209168414, 476607030432890] |