The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 18 |
| 2 | 180 |
| 3 | 1728 |
| 4 | 16560 |
| 5 | 159048 |
| 6 | 1531440 |
| 7 | 14782968 |
| 8 | 143046720 |
| 9 | 1387420488 |
| 10 | 13486784400 |
| 11 | 131381059608 |
| 12 | 1282429536480 |
| 13 | 12541865828328 |
| 14 | 122876792454960 |
| 15 | 1205891132094648 |
| 16 | 11853020188851840 |
| 17 | 116677181699666568 |
[1,18,180,1728,16560,159048,1531440,14782968, 143046720,1387420488,13486784400,131381059608, 1282429536480,12541865828328,122876792454960, 1205891132094648,11853020188851840, 116677181699666568] |