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 | -12 |
| 2 | 78 |
| 3 | -376 |
| 4 | 1509 |
| 5 | -5316 |
| 6 | 16966 |
| 7 | -50088 |
| 8 | 138738 |
| 9 | -364284 |
| 10 | 913824 |
| 11 | -2203368 |
| 12 | 5130999 |
| 13 | -11585208 |
| 14 | 25444278 |
| 15 | -54504160 |
| 16 | 114133296 |
| 17 | -234091152 |
| 18 | 471062830 |
| 19 | -931388232 |
| 20 | 1811754522 |
| 21 | -3471186596 |
| 22 | 6556994502 |
| 23 | -12222818640 |
| 24 | 22502406793 |