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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | -2 |
| 4 | 4 |
| 5 | -7 |
| 6 | 10 |
| 7 | -10 |
| 8 | 0 |
| 9 | 35 |
| 10 | -125 |
| 11 | 325 |
| 12 | -725 |
| 13 | 1451 |
| 14 | -2639 |
| 15 | 4355 |
| 16 | -6435 |
| 17 | 8255 |
| 18 | -8567 |
| 19 | 5863 |
| 20 | -455 |
| 21 | 910 |
| 22 | -40105 |
| 23 | 210418 |
| 24 | -733447 |
| 25 | 2085525 |
| 26 | -5200299 |
| 27 | 11748373 |
| 28 | -24416951 |
| 29 | 46909837 |
| 30 | -82930835 |
| 31 | 132479945 |
| 32 | -182029055 |
| 33 | 182029055 |
| 34 | 1 |
| 35 | -670853985 |
| 36 | 2480588545 |