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 | 0 |
| 2 | -3 |
| 3 | 2 |
| 4 | -8 |
| 5 | 9 |
| 6 | -23 |
| 7 | 33 |
| 8 | -70 |
| 9 | 113 |
| 10 | -220 |
| 11 | 376 |
| 12 | -703 |
| 13 | 1235 |
| 14 | -2265 |
| 15 | 4032 |
| 16 | -7327 |
| 17 | 13126 |
| 18 | -23748 |
| 19 | 42673 |
| 20 | -77043 |
| 21 | 138641 |
| 22 | -250054 |
| 23 | 450293 |
| 24 | -811760 |
| 25 | 1462292 |
| 26 | -2635519 |
| 27 | 4748343 |
| 28 | -8557089 |
| 29 | 15418256 |
| 30 | -27784091 |
| 31 | 50063514 |
| 32 | -90213440 |
| 33 | 162556377 |
| 34 | -292919743 |