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 | 3 |
| 2 | -89 |
| 3 | -855 |
| 4 | 23601 |
| 5 | 405963 |
| 6 | -10346601 |
| 7 | -269746047 |
| 8 | 6288530145 |
| 9 | 230346491283 |
| 10 | -4855444114041 |
| 11 | -240305893799463 |
| 12 | 4513251073537809 |
| 13 | 296139484328781915 |
| 14 | -4861463414700822921 |
| 15 | -420887762743191256143 |
| 16 | 5883687931380635925441 |
| 17 | 677603075775465797408547 |