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 | -1 |
| 2 | -3 |
| 3 | -2 |
| 4 | 15 |
| 5 | 62 |
| 6 | 56 |
| 7 | -566 |
| 8 | -3318 |
| 9 | -6241 |
| 10 | 33022 |
| 11 | 330939 |
| 12 | 1211873 |
| 13 | -1330691 |
| 14 | -47459905 |
| 15 | -310788796 |
| 16 | -675462411 |
| 17 | 7151217040 |
| 18 | 93213242926 |
| 19 | 515144576280 |
| 20 | 122725585740 |
| 21 | -27551616750331 |
| 22 | -296570472858772 |
| 23 | -1477869678576483 |
| 24 | 3416889475636695 |
| 25 | 146832017085068163 |
| 26 | 1522825949942199537 |