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 | -3 |
| 2 | -13 |
| 3 | 27 |
| 4 | 52791 |
| 5 | 482427 |
| 6 | -124996631 |
| 7 | -5270328789 |
| 8 | -7479063506161 |
| 9 | 6921977624613 |
| 10 | 10703530420192887741 |
| 11 | -31023547697719285017327 |
| 12 | 4502691897987538544182239 |
| 13 | -201974203900639732887399429 |
| 14 | 632827656013898657214770949567 |
| 15 | -1732419272534268233524732551 |