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 | 3 |
| 3 | 0 |
| 4 | -27 |
| 5 | 0 |
| 6 | 243 |
| 7 | 0 |
| 8 | -2187 |
| 9 | 0 |
| 10 | 98415 |
| 11 | 0 |
| 12 | -122408577 |
| 13 | 0 |
| 14 | 11160261 |
| 15 | 0 |
| 16 | -51899996619 |
| 17 | 0 |
| 18 | 5664991530321 |
| 19 | 0 |
| 20 | -202943637014337 |
| 21 | 0 |
| 22 | 8938507796555139 |
| 23 | 0 |
| 24 | -22252066887294301257 |
| 25 | 0 |
| 26 | 7246946747292751629 |
| 27 | 0 |
| 28 | -181103830292539169071623 |