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 | -2 |
| 3 | 26 |
| 4 | -229 |
| 5 | 3181 |
| 6 | -59700 |
| 7 | 1469380 |
| 8 | -45938639 |
| 9 | 1779367231 |
| 10 | -83663906454 |
| 11 | 4695118012798 |
| 12 | -310029578255977 |
| 13 | 23797509154723361 |
| 14 | -2101268283286737704 |
| 15 | 211490399673452191176 |
| 16 | -24070116208693613274035 |
| 17 | 3075833697885980827017235 |
| 18 | -438528974913900528707713514 |