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 | 1 |
| 3 | 0 |
| 4 | -1 |
| 5 | 1 |
| 6 | 0 |
| 7 | 7 |
| 8 | -3 |
| 9 | 1 |
| 10 | 0 |
| 11 | -61 |
| 12 | 31 |
| 13 | -6 |
| 14 | 1 |
| 15 | 0 |
| 16 | 751 |
| 17 | -375 |
| 18 | 85 |
| 19 | -10 |
| 20 | 1 |
| 21 | 0 |
| 22 | -11821 |
| 23 | 5911 |
| 24 | -1350 |
| 25 | 185 |
| 26 | -15 |
| 27 | 1 |
| 28 | 0 |
| 29 | 226927 |
| 30 | -113463 |
| 31 | 26341 |
| 32 | -3710 |
| 33 | 350 |
| 34 | -21 |
| 35 | 1 |
| 36 | 0 |
| 37 | -5142061 |
| 38 | 2571031 |
| 39 | -603246 |
| 40 | 87381 |
| 41 | -8610 |
| 42 | 602 |
| 43 | -28 |
| 44 | 1 |
| 45 | 0 |
| 46 | 134341711 |
| 47 | -67170855 |
| 48 | 15887845 |
| 49 | -2346330 |
| 50 | 240051 |
| 51 | -17766 |