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) |
|---|---|
| 1 | -1 |
| 2 | -1 |
| 3 | -1 |
| 4 | -5 |
| 5 | -7 |
| 6 | -15 |
| 7 | -7601 |
| 8 | -91 |
| 9 | -3617 |
| 10 | -745739 |
| 11 | -3317609 |
| 12 | -5981591 |
| 13 | -5436374093 |
| 14 | -213827575 |
| 15 | -213745149261 |
| 16 | -249859397004145 |
| 17 | -238988952277727 |
| 18 | -28354566442037 |
| 19 | -26315271553053477373 |
| 20 | -108409774812137683 |
| 21 | -3394075340453838586663 |
| 22 | -62324003400640902910331 |