The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 18 |
| 2 | 2536 |
| 3 | 1136101 |
| 4 | 119227930 |
| 5 | 33636581266 |
| 6 | 1774960492720 |
| 7 | 685318499093455 |
[0,18,2536,1136101,119227930,33636581266, 1774960492720,685318499093455] |