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 | -4 |
| 3 | 44 |
| 4 | -428 |
| 5 | 10196 |
| 6 | -10719068 |
| 7 | 25865068 |
| 8 | -5472607916 |
| 9 | 74185965772 |
| 10 | -264698472181028 |
| 11 | 2290048394728148 |
| 12 | -19435959308462817284 |
| 13 | 2753151578548809148 |
| 14 | -20586893910854623222436 |
| 15 | 134344844535611780572028924 |