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 | -19 |
| 3 | 475 |
| 4 | 1753 |
| 5 | -1109769 |
| 6 | 70784325 |
| 7 | 2711086547 |
| 8 | -1376283649103 |
| 9 | 148592152807663 |
| 10 | 21812320857733789 |
| 11 | -12754009647903010101 |
| 12 | 1675171082535404962441 |
| 13 | 847081835857552788679655 |