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 | -9 |
| 3 | -41 |
| 4 | -241 |
| 5 | -271 |
| 6 | 27329 |
| 7 | 651521 |
| 8 | 18425809 |
| 9 | 399122991 |
| 10 | -24055184809 |
| 11 | -3943757411849 |
| 12 | -498726356978849 |
| 13 | -74609317288333151 |
| 14 | 2771780972000481601 |
| 15 | 8459493968101503667649 |
| 16 | 5139175203350482789079649 |