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 | -2 |
| 3 | 9 |
| 4 | -68 |
| 5 | 725 |
| 6 | -9966 |
| 7 | 167629 |
| 8 | -3334120 |
| 9 | 76543785 |
| 10 | -1992009850 |
| 11 | 57948521521 |
| 12 | -1863394764780 |
| 13 | 65631109286717 |
| 14 | -2512768138160294 |
| 15 | 103905545328667125 |
| 16 | -4615035074291158352 |
| 17 | 219122841820491458897 |
| 18 | -11075488610594107402098 |
| 19 | 593746153204862664363481 |