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 | 7 |
| 2 | 11 |
| 3 | 7 |
| 4 | 19 |
| 5 | 337 |
| 6 | 5 |
| 7 | -1681 |
| 8 | 22133 |
| 9 | -87223 |
| 10 | 427291 |
| 11 | -118181363 |
| 12 | 4276553 |
| 13 | -11874730297 |
| 14 | 4307920641583 |
| 15 | -3854660520481 |
| 16 | 1288843929185 |
| 17 | -13157635776526258889 |
| 18 | 1464996956920781 |
| 19 | -130541359248224557643 |