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 | -3 |
| 3 | 1 |
| 4 | 11 |
| 5 | -16 |
| 6 | -35 |
| 7 | -129 |
| 8 | 299 |
| 9 | -386 |
| 10 | -3977 |
| 11 | 8063 |
| 12 | 42489 |
| 13 | 269344 |
| 14 | -1000009 |
| 15 | 3727745 |
| 16 | 47166649 |
| 17 | -123526014 |
| 18 | -1764203419 |
| 19 | -18228952703 |
| 20 | 113727892147 |
| 21 | -1065812586544 |
| 22 | -18344075481339 |
| 23 | 52130069331199 |
| 24 | 2470319425874195 |