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 | -2 |
| 2 | 2 |
| 3 | -4 |
| 4 | 8 |
| 5 | -12 |
| 6 | 20 |
| 7 | -36 |
| 8 | 60 |
| 9 | -100 |
| 10 | 172 |
| 11 | -292 |
| 12 | 492 |
| 13 | -836 |
| 14 | 1420 |
| 15 | -2404 |
| 16 | 4076 |
| 17 | -6916 |
| 18 | 11724 |
| 19 | -19876 |
| 20 | 33708 |
| 21 | -57156 |
| 22 | 96908 |
| 23 | -164324 |
| 24 | 278636 |
| 25 | -472452 |
| 26 | 801100 |
| 27 | -1358372 |
| 28 | 2303276 |
| 29 | -3905476 |
| 30 | 6622220 |
| 31 | -11228772 |
| 32 | 19039724 |
| 33 | -32284164 |
| 34 | 54741708 |
| 35 | -92821156 |
| 36 | 157389484 |
| 37 | -266872900 |