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 | 0 |
| 1 | 1 |
| 2 | -5 |
| 3 | 14 |
| 4 | -23 |
| 5 | 349 |
| 6 | -499 |
| 7 | 793 |
| 8 | -1038 |
| 9 | 7901 |
| 10 | -9791 |
| 11 | 65488 |
| 12 | -78193 |
| 13 | 795259 |
| 14 | -925389 |
| 15 | 1615811 |
| 16 | -1841036 |
| 17 | 67142767 |
| 18 | -75821437 |
| 19 | 358067518 |
| 20 | -388783203 |
| 21 | -521129621 |
| 22 | 480390923 |
| 23 | 133108162049 |