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 | -15 |
| 2 | 75 |
| 3 | -50 |
| 4 | -750 |
| 5 | 1797 |
| 6 | 2220 |
| 7 | -6975 |
| 8 | -13980 |
| 9 | 6220 |
| 10 | 125682 |
| 11 | -8910 |
| 12 | -387885 |
| 13 | -365160 |
| 14 | 62130 |
| 15 | 3177433 |
| 16 | 2777445 |
| 17 | -3799695 |
| 18 | -17320915 |
| 19 | -28897950 |
| 20 | 39859074 |
| 21 | 105240645 |
| 22 | 131649465 |
| 23 | -50100225 |
| 24 | -602800010 |
| 25 | -882445182 |