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 | 0 |
| 4 | 1 |
| 5 | -2 |
| 6 | 3 |
| 7 | 1 |
| 8 | -5 |
| 9 | 10 |
| 10 | 0 |
| 11 | 1 |
| 12 | -9 |
| 13 | 31 |
| 14 | -39 |
| 15 | 40 |
| 16 | 1 |
| 17 | -14 |
| 18 | 77 |
| 19 | -196 |
| 20 | 252 |
| 21 | 0 |
| 22 | 1 |
| 23 | -20 |
| 24 | 162 |
| 25 | -664 |
| 26 | 1457 |
| 27 | -1476 |
| 28 | 1260 |
| 29 | 1 |
| 30 | -27 |
| 31 | 303 |
| 32 | -1809 |
| 33 | 6168 |
| 34 | -11772 |
| 35 | 12176 |
| 36 | 0 |
| 37 | 1 |
| 38 | -35 |
| 39 | 520 |
| 40 | -4250 |
| 41 | 20773 |
| 42 | -61595 |
| 43 | 107730 |
| 44 | -95400 |
| 45 | 72576 |
| 46 | 1 |
| 47 | -44 |
| 48 | 836 |
| 49 | -8954 |
| 50 | 59279 |
| 51 | -249986 |