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 | -19 |
| 2 | 167 |
| 3 | -665 |
| 4 | 46813 |
| 5 | -28595 |
| 6 | 2200847 |
| 7 | -942305 |
| 8 | 69637093 |
| 9 | -37919231 |
| 10 | -1583934365 |
| 11 | 454005475 |
| 12 | 65901450175543 |
| 13 | -483633563387 |
| 14 | -49846844511751 |
| 15 | 195284370031975 |
| 16 | 2100079369556583701 |
| 17 | -109471609351004663 |
| 18 | -2062327986071160493171 |
| 19 | 76800003085530485995 |