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 | -8 |
| 3 | -1 |
| 4 | 217 |
| 5 | 1196 |
| 6 | -3725 |
| 7 | -115777 |
| 8 | -803150 |
| 9 | 3402485 |
| 10 | 145172737 |
| 11 | 1528780238 |
| 12 | -1328359499 |
| 13 | -320347469485 |
| 14 | -5507171702648 |
| 15 | -28294413916213 |
| 16 | 915647446089037 |
| 17 | 28738067698188692 |
| 18 | 369693788462739487 |
| 19 | -1233559476327263869 |