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 | 2 |
| 2 | -4 |
| 3 | -88 |
| 4 | 5360 |
| 5 | 1395104 |
| 6 | -1423111744 |
| 7 | -5834786588032 |
| 8 | 95573832673124096 |
| 9 | 6263909110244685920768 |
| 10 | -1642021136070472933898232832 |
| 11 | -1721790522986063937046243536001024 |
| 12 | 7221705990593287793620261453916626546688 |
| 13 | 121160150179535955805047509278599956409746825216 |