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 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | -3 |
| 4 | -23 |
| 5 | -83 |
| 6 | -119 |
| 7 | 973 |
| 8 | 11145 |
| 9 | 69805 |
| 10 | 278281 |
| 11 | 33165 |
| 12 | -12794231 |
| 13 | -157150355 |
| 14 | -1271714807 |
| 15 | -7108146611 |
| 16 | -11364216951 |
| 17 | 380051588653 |
| 18 | 6923479542025 |
| 19 | 78935931180813 |
| 20 | 669998027706505 |
| 21 | 3602978599128301 |
| 22 | -8825050911646199 |
| 23 | -598024924863875123 |