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 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 8 |
| 6 | 13 |
| 7 | -64 |
| 8 | -855 |
| 9 | -5632 |
| 10 | -38791 |
| 11 | -205184 |
| 12 | -747539 |
| 13 | -240640 |
| 14 | 59637061 |
| 15 | 859820032 |
| 16 | 9421489105 |
| 17 | 90170851328 |
| 18 | 573991066225 |
| 19 | 1502445600768 |
| 20 | -49290541346219 |
| 21 | -1320541298393088 |
| 22 | -20481513828195331 |
| 23 | -272882319216148480 |