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 | 0 |
| 1 | 1 |
| 2 | -1 |
| 3 | 1 |
| 4 | -1 |
| 5 | -1 |
| 6 | 5 |
| 7 | -8 |
| 8 | 7 |
| 9 | 1 |
| 10 | -19 |
| 11 | 43 |
| 12 | -55 |
| 13 | 27 |
| 14 | 64 |
| 15 | -211 |
| 16 | 343 |
| 17 | -307 |
| 18 | -85 |
| 19 | 911 |
| 20 | -1919 |
| 21 | 2344 |
| 22 | -989 |
| 23 | -3151 |
| 24 | 9625 |
| 25 | -15049 |
| 26 | 12609 |
| 27 | 5671 |
| 28 | -42496 |
| 29 | 85609 |
| 30 | -100225 |
| 31 | 33977 |
| 32 | 154007 |
| 33 | -437009 |
| 34 | 657901 |
| 35 | -513512 |
| 36 | -335665 |
| 37 | 1974097 |
| 38 | -3808891 |
| 39 | 4265379 |