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 | 1 |
| 5 | -1 |
| 6 | 0 |
| 7 | 1 |
| 8 | -1 |
| 9 | 0 |
| 10 | -1 |
| 11 | 1 |
| 12 | -1 |
| 13 | 2 |
| 14 | 1 |
| 15 | 1 |
| 16 | 1 |
| 17 | -1 |
| 18 | 9 |
| 19 | -1 |
| 20 | 1 |
| 21 | -1 |
| 22 | 1 |
| 23 | -1 |
| 24 | 34 |
| 25 | -197 |
| 26 | -43 |
| 27 | -2 |
| 28 | 1 |
| 29 | 1 |
| 30 | -1 |
| 31 | 125 |
| 32 | -5281 |
| 33 | 6841 |
| 34 | 254 |
| 35 | -9 |
| 36 | -1 |
| 37 | 1 |
| 38 | -1 |
| 39 | 461 |
| 40 | -123124 |
| 41 | 2185429 |
| 42 | -254801 |
| 43 | 4157 |
| 44 | -9 |
| 45 | 2 |
| 46 | 1 |
| 47 | -1 |
| 48 | 1715 |
| 49 | -2840293 |
| 50 | 465693001 |
| 51 | -1854147586 |
| 52 | -3000807 |
| 53 | -70981 |
| 54 | 50 |
| 55 | -2 |