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 | 2 |
| 1 | 1 |
| 2 | -1 |
| 3 | -2 |
| 4 | 1 |
| 5 | 6 |
| 6 | -3 |
| 7 | -34 |
| 8 | 17 |
| 9 | 310 |
| 10 | -155 |
| 11 | -4146 |
| 12 | 2073 |
| 13 | 76454 |
| 14 | -38227 |
| 15 | -1859138 |
| 16 | 929569 |
| 17 | 57641238 |
| 18 | -28820619 |
| 19 | -2219305810 |
| 20 | 1109652905 |
| 21 | 103886563462 |
| 22 | -51943281731 |
| 23 | -5810302084962 |
| 24 | 2905151042481 |
| 25 | 382659344967926 |