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 | 1 |
| 2 | -1 |
| 3 | -3 |
| 4 | 1 |
| 5 | 5 |
| 6 | -1 |
| 7 | -7 |
| 8 | 1 |
| 9 | 9 |
| 10 | -1 |
| 11 | -11 |
| 12 | 1 |
| 13 | 13 |
| 14 | -1 |
| 15 | -15 |
| 16 | 1 |
| 17 | 17 |
| 18 | -1 |
| 19 | -19 |
| 20 | 1 |
| 21 | 21 |
| 22 | -1 |
| 23 | -23 |
| 24 | 1 |
| 25 | 25 |
| 26 | -1 |
| 27 | -27 |
| 28 | 1 |
| 29 | 29 |
| 30 | -1 |
| 31 | -31 |
| 32 | 1 |
| 33 | 33 |
| 34 | -1 |
| 35 | -35 |
| 36 | 1 |
| 37 | 37 |
| 38 | -1 |
| 39 | -39 |
| 40 | 1 |
| 41 | 41 |
| 42 | -1 |
| 43 | -43 |
| 44 | 1 |
| 45 | 45 |
| 46 | -1 |
| 47 | -47 |
| 48 | 1 |
| 49 | 49 |
| 50 | -1 |
| 51 | -51 |
| 52 | 1 |
| 53 | 53 |
| 54 | -1 |
| 55 | -55 |
| 56 | 1 |
| 57 | 57 |
| 58 | -1 |
| 59 | -59 |
| 60 | 1 |
| 61 | 61 |
| 62 | -1 |
| 63 | -63 |
| 64 | 1 |
| 65 | 65 |
| 66 | -1 |
| 67 | -67 |
| 68 | 1 |
| 69 | 69 |
| 70 | -1 |
| 71 | -71 |
| 72 | 1 |
| 73 | 73 |
| 74 | -1 |
| 75 | -75 |
| 76 | 1 |
| 77 | 77 |
| 78 | -1 |
| 79 | -79 |
| 80 | 1 |
| 81 | 81 |
| 82 | -1 |
| 83 | -83 |
| 84 | 1 |
| 85 | 85 |