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 | 0 |
| 3 | 1 |
| 4 | -2 |
| 5 | 5 |
| 6 | -14 |
| 7 | 37 |
| 8 | -90 |
| 9 | 205 |
| 10 | -442 |
| 11 | 899 |
| 12 | -1700 |
| 13 | 2913 |
| 14 | -4302 |
| 15 | 4747 |
| 16 | -1080 |
| 17 | -14001 |
| 18 | 55336 |
| 19 | -150395 |
| 20 | 346164 |
| 21 | -716967 |
| 22 | 1369430 |
| 23 | -2432789 |
| 24 | 4002994 |
| 25 | -5964749 |
| 26 | 7525018 |
| 27 | -6123027 |
| 28 | -4900092 |
| 29 | 40900519 |
| 30 | -134308944 |
| 31 | 348584679 |
| 32 | -798958750 |