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 | 9 |
| 2 | -29 |
| 3 | 61 |
| 4 | -17 |
| 5 | -263 |
| 6 | 1019 |
| 7 | -2027 |
| 8 | 1639 |
| 9 | 4625 |
| 10 | -22989 |
| 11 | 52717 |
| 12 | -62369 |
| 13 | -43863 |
| 14 | 426475 |
| 15 | -1159355 |
| 16 | 1757143 |
| 17 | -366911 |
| 18 | -6668509 |
| 19 | 22627357 |
| 20 | -41707313 |
| 21 | 31494233 |
| 22 | 83699163 |
| 23 | -398658443 |
| 24 | 880521031 |
| 25 | -1018619535 |
| 26 | -628523501 |
| 27 | 6333704269 |
| 28 | -16958792897 |
| 29 | 25462262281 |
| 30 | -6426619957 |
| 31 | -88626976859 |