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 | 1 |
| 3 | 5 |
| 4 | 8 |
| 5 | -1 |
| 6 | 27 |
| 7 | 57 |
| 8 | -15 |
| 9 | 3 |
| 10 | 502 |
| 11 | 1292 |
| 12 | -528 |
| 13 | 212 |
| 14 | -38 |
| 15 | 2375 |
| 16 | 7135 |
| 17 | -3990 |
| 18 | 2410 |
| 19 | -865 |
| 20 | 135 |