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 | 1 |
| 4 | 0 |
| 5 | -4 |
| 6 | -14 |
| 7 | -34 |
| 8 | -68 |
| 9 | -116 |
| 10 | -164 |
| 11 | -164 |
| 12 | 0 |
| 13 | 560 |
| 14 | 1912 |
| 15 | 4616 |
| 16 | 9232 |
| 17 | 15760 |
| 18 | 22288 |
| 19 | 22288 |
| 20 | 0 |
| 21 | -76096 |
| 22 | -259808 |
| 23 | -627232 |
| 24 | -1254464 |
| 25 | -2141504 |
| 26 | -3028544 |
| 27 | -3028544 |
| 28 | 0 |
| 29 | 10340096 |
| 30 | 35303296 |
| 31 | 85229696 |
| 32 | 170459392 |
| 33 | 290992384 |
| 34 | 411525376 |
| 35 | 411525376 |
| 36 | 0 |
| 37 | -1405035520 |