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 | 0 |
| 2 | 0 |
| 3 | 4 |
| 4 | -4 |
| 5 | 4 |
| 6 | 8 |
| 7 | -20 |
| 8 | 32 |
| 9 | -12 |
| 10 | -40 |
| 11 | 124 |
| 12 | -160 |
| 13 | 68 |
| 14 | 232 |
| 15 | -628 |
| 16 | 816 |
| 17 | -300 |
| 18 | -1160 |
| 19 | 3100 |
| 20 | -3904 |
| 21 | 1380 |
| 22 | 5640 |
| 23 | -14676 |
| 24 | 18256 |
| 25 | -6156 |
| 26 | -26472 |
| 27 | 67900 |
| 28 | -83488 |
| 29 | 27268 |
| 30 | 121640 |
| 31 | -308276 |
| 32 | 375920 |
| 33 | -119532 |
| 34 | -549448 |
| 35 | 1379932 |
| 36 | -1671424 |
| 37 | 520100 |
| 38 | 2449480 |