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 | 1 |
| 2 | -3 |
| 3 | -30 |
| 4 | -30 |
| 5 | -3155 |
| 6 | 43501 |
| 7 | -780042 |
| 8 | -780042 |
| 9 | -780042 |
| 10 | 9999219958 |
| 11 | -275312450653 |
| 12 | -275312450653 |
| 13 | -303150419042906 |
| 14 | 10808856406515110 |
| 15 | 448702746787374485 |
| 16 | 448702746787374485 |
| 17 | -826791559139549389692 |
| 18 | -826791559139549389692 |