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 | 1 |
| 2 | 0 |
| 3 | -2 |
| 4 | -1 |
| 5 | 11 |
| 6 | 13 |
| 7 | -111 |
| 8 | -220 |
| 9 | 1756 |
| 10 | 5051 |
| 11 | -39775 |
| 12 | -153191 |
| 13 | 1215345 |
| 14 | 5952668 |
| 15 | -48020714 |
| 16 | -288569149 |
| 17 | 2377190003 |
| 18 | 17069110381 |
| 19 | -143857868895 |
| 20 | -1209439895944 |
| 21 | 10435153277620 |
| 22 | 101078662547567 |
| 23 | -892827447251575 |
| 24 | -9834570608359487 |
| 25 | 88900938146195601 |
| 26 | 1101567283699652888 |