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 | -25 |
| 2 | 275 |
| 3 | -1700 |
| 4 | 6050 |
| 5 | -9405 |
| 6 | -15550 |
| 7 | 107525 |
| 8 | -182875 |
| 9 | -81675 |
| 10 | 756655 |
| 11 | -801550 |
| 12 | -662975 |
| 13 | 1220175 |
| 14 | 1361350 |
| 15 | -209440 |
| 16 | -9601900 |
| 17 | 8608900 |
| 18 | 14889050 |
| 19 | -19948500 |
| 20 | -6262465 |
| 21 | -7057550 |
| 22 | 38788925 |
| 23 | 19716425 |
| 24 | -69119875 |
| 25 | 23579969 |
| 26 | -82427400 |
| 27 | 98068850 |
| 28 | 191984400 |