The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 20 |
| 3 | 366 |
| 4 | 9992 |
| 5 | 365130 |
| 6 | 16769292 |
| 7 | 929022206 |
| 8 | 60323670416 |
| 9 | 4494465562770 |
| 10 | 378025706776340 |
| 11 | 35434198578761862 |
| 12 | 3663111561838580568 |
| 13 | 414057463231218044186 |
| 14 | 50805545997014472821276 |
| 15 | 6725525908390393438264590 |
| 16 | 955435863749903677193184032 |
| 17 | 144987884255349864723586105122 |
[1,2,20,366,9992,365130,16769292,929022206, 60323670416,4494465562770,378025706776340, 35434198578761862,3663111561838580568, 414057463231218044186,50805545997014472821276, 6725525908390393438264590, 955435863749903677193184032, 144987884255349864723586105122] |