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 | 2 |
| 2 | 0 |
| 3 | 1 |
| 4 | -3 |
| 5 | 7 |
| 6 | -15 |
| 7 | 31 |
| 8 | -63 |
| 9 | 127 |
| 10 | -255 |
| 11 | 510 |
| 12 | -1011 |
| 13 | 1968 |
| 14 | -3717 |
| 15 | 6720 |
| 16 | -11439 |
| 17 | 17874 |
| 18 | -24309 |
| 19 | 24309 |
| 20 | 0 |
| 21 | -92358 |
| 22 | 352485 |
| 23 | -997569 |
| 24 | 2485242 |
| 25 | -5754024 |
| 26 | 12680955 |
| 27 | -26924184 |
| 28 | 55410642 |
| 29 | -110821283 |
| 30 | 215426355 |
| 31 | -406270425 |
| 32 | 740354804 |
| 33 | -1294617072 |
| 34 | 2145852303 |