This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 2 |
| 3 | 9 |
| 4 | 80 |
| 5 | 875 |
| 6 | 11880 |
| 7 | 192080 |
| 8 | 3608576 |
| 9 | 77295141 |
| 10 | 1860100000 |
| 11 | 49701143855 |
| 12 | 1460328321024 |
| 13 | 46805373800640 |
| 14 | 1625353003293824 |
| 15 | 60796114850390625 |
| 16 | 2437185999638364160 |
| 17 | 104248664384022862523 |
| 18 | 4739500894223556407808 |