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) |
|---|---|
| 0 | 1 |
| 1 | 12 |
| 2 | 30 |
| 3 | 76 |
| 4 | -819 |
| 5 | 15120 |
| 6 | -320568 |
| 7 | 7719984 |
| 8 | -208986462 |
| 9 | 6300545128 |
| 10 | -209806494828 |
| 11 | 7660698340008 |
| 12 | -304718887446110 |
| 13 | 13127557400200944 |
| 14 | -609336227455254936 |
| 15 | 30330991088734345200 |
| 16 | -1612305658103085757467 |
| 17 | 91179423240593288760396 |
| 18 | -5467060640706775435713298 |