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 | 9 |
| 3 | -128 |
| 4 | 2500 |
| 5 | -62208 |
| 6 | 1882384 |
| 7 | -67108864 |
| 8 | 2754990144 |
| 9 | -128000000000 |
| 10 | 6639980697856 |
| 11 | -380420285792256 |
| 12 | 23857239165420544 |
| 13 | -1625527855624486912 |
| 14 | 119574225000000000000 |
| 15 | -9444732965739290427392 |