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 | -4 |
| 4 | 7 |
| 5 | -17 |
| 6 | 23 |
| 7 | -89 |
| 8 | 7 |
| 9 | 28 |
| 10 | 112 |
| 11 | 448 |
| 12 | 1792 |
| 13 | -4417 |
| 14 | 5503 |
| 15 | 22012 |
| 16 | -4633 |
| 17 | -18532 |
| 18 | -74128 |
| 19 | -296512 |
| 20 | 296863 |
| 21 | 1187452 |
| 22 | -1181833 |
| 23 | -4727332 |
| 24 | 4817239 |
| 25 | 19268956 |
| 26 | -17830441 |
| 27 | -71321764 |
| 28 | 94338007 |
| 29 | 377352028 |
| 30 | -9092137 |
| 31 | -36368548 |
| 32 | -145474192 |
| 33 | -581896768 |
| 34 | -2327587072 |
| 35 | -9310348288 |