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 | 5 |
| 3 | -1 |
| 4 | 1 |
| 5 | 1 |
| 6 | -5 |
| 7 | -1 |
| 8 | 7 |
| 9 | 3 |
| 10 | -15 |
| 11 | -5 |
| 12 | 7601 |
| 13 | 691 |
| 14 | -91 |
| 15 | -35 |
| 16 | 3617 |
| 17 | 3617 |
| 18 | -745739 |
| 19 | -43867 |
| 20 | 3317609 |
| 21 | 1222277 |
| 22 | -5981591 |
| 23 | -854513 |
| 24 | 5436374093 |
| 25 | 1181820455 |
| 26 | -213827575 |
| 27 | -76977927 |
| 28 | 213745149261 |
| 29 | 23749461029 |
| 30 | -249859397004145 |
| 31 | -8615841276005 |
| 32 | 238988952277727 |
| 33 | 84802531453387 |