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 | -1 |
| 3 | -5 |
| 4 | -5 |
| 5 | 11 |
| 6 | 41 |
| 7 | 29 |
| 8 | -125 |
| 9 | -365 |
| 10 | -131 |
| 11 | 1409 |
| 12 | 3301 |
| 13 | -155 |
| 14 | -15625 |
| 15 | -29485 |
| 16 | 16115 |
| 17 | 170035 |
| 18 | 254525 |
| 19 | -309775 |
| 20 | -1813055 |
| 21 | -2064655 |
| 22 | 4617755 |
| 23 | 18909175 |
| 24 | 14903725 |
| 25 | -61552739 |
| 26 | -192390589 |
| 27 | -81290561 |
| 28 | 767919595 |
| 29 | 1901796395 |
| 30 | 28588201 |