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 | 2 |
| 2 | -2 |
| 3 | -2 |
| 4 | 10 |
| 5 | -6 |
| 6 | -42 |
| 7 | 102 |
| 8 | 82 |
| 9 | -782 |
| 10 | 814 |
| 11 | 3854 |
| 12 | -12454 |
| 13 | -5014 |
| 14 | 98694 |
| 15 | -142218 |
| 16 | -472158 |
| 17 | 1932258 |
| 18 | 19038 |
| 19 | -14816994 |
| 20 | 27370410 |
| 21 | 64159962 |
| 22 | -334154442 |
| 23 | 121279878 |
| 24 | 2418497010 |
| 25 | -5523511086 |
| 26 | -8914677362 |
| 27 | 61259567662 |
| 28 | -44249714438 |