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 | 0 |
| 4 | -3 |
| 5 | -2 |
| 6 | 23 |
| 7 | 17 |
| 8 | -333 |
| 9 | 86 |
| 10 | 6941 |
| 11 | -17025 |
| 12 | -160267 |
| 13 | 1082864 |
| 14 | 2273807 |
| 15 | -56742606 |
| 16 | 152154285 |
| 17 | 2293098332 |
| 18 | -22007462809 |
| 19 | -15179437171 |
| 20 | 1671107690083 |
| 21 | -10716783889040 |
| 22 | -58404948615167 |
| 23 | 1439391012463810 |
| 24 | -6701658223127029 |
| 25 | -88340107011433060 |