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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 2 |
| 6 | -5 |
| 7 | 12 |
| 8 | -28 |
| 9 | 32 |
| 10 | -36 |
| 11 | -44 |
| 12 | -51 |
| 13 | 90 |
| 14 | -129 |
| 15 | -572 |
| 16 | 560 |
| 17 | -228 |
| 18 | -1265 |
| 19 | -3752 |
| 20 | -7344 |
| 21 | -7168 |
| 22 | -5200 |
| 23 | -1800 |
| 24 | 22225 |
| 25 | -223908 |
| 26 | -3353049 |
| 27 | -16485870 |
| 28 | -46205099 |
| 29 | 57203700 |
| 30 | 262750475 |
| 31 | -1758254750 |
| 32 | -4839494944 |
| 33 | -8039222088 |
| 34 | 8145218368 |
| 35 | 45619374914 |
| 36 | -1229448140891 |
| 37 | -1178481640872 |
| 38 | -942903100573 |
| 39 | 1256162791268 |
| 40 | -805110454771 |