The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 21 |
| 3 | 10981 |
| 4 | 252081 |
| 5 | 132846121 |
| 6 | 3049673901 |
| 7 | 1607172358861 |
| 8 | 36894954600201 |
| 9 | 19443571064652241 |
| 10 | 446355157703555781 |
| 11 | 235228321132990450741 |
| 12 | 5400004661002663236321 |
| 13 | 2845792209623347408410361 |
| 14 | 65329255942455062129453661 |
| 15 | 34428393916794935813958094621 |
[1,21,10981,252081,132846121,3049673901, 1607172358861,36894954600201,19443571064652241, 446355157703555781,235228321132990450741, 5400004661002663236321,2845792209623347408410361, 65329255942455062129453661, 34428393916794935813958094621] |