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 | 2 |
| 3 | -5 |
| 4 | -28 |
| 5 | 85 |
| 6 | 806 |
| 7 | -3185 |
| 8 | -41656 |
| 9 | 207913 |
| 10 | 3428810 |
| 11 | -20824925 |
| 12 | -413027284 |
| 13 | 2961364861 |
| 14 | 68560259054 |
| 15 | -567040692425 |
| 16 | -15005357203312 |
| 17 | 140642298254929 |
| 18 | 4187120881320338 |
| 19 | -43861384856264885 |
| 20 | -1450918780756640140 |
| 21 | 16798626454194814117 |
| 22 | 611263061851828001462 |
| 23 | -7751163512199032905505 |