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 | -1 |
| 3 | 1 |
| 4 | 19 |
| 5 | 25031 |
| 6 | 18421 |
| 7 | -622177 |
| 8 | -283401163 |
| 9 | -24826632949 |
| 10 | -2243454779 |
| 11 | 4882905709651 |
| 12 | 43798187793808543 |
| 13 | -46704901267812186793 |
| 14 | -5325187532598955153807 |