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 | 0 |
| 2 | -1 |
| 3 | -3 |
| 4 | -17 |
| 5 | -153 |
| 6 | -1846 |
| 7 | -27828 |
| 8 | -503000 |
| 9 | -10599873 |
| 10 | -255143728 |
| 11 | -6906078108 |
| 12 | -207627211745 |
| 13 | -6864486246225 |
| 14 | -247526246562328 |
| 15 | -9667515778323735 |
| 16 | -406560434763167342 |
| 17 | -18316445888374834635 |
| 18 | -880110629723965618045 |
| 19 | -44928348211160605056537 |