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 | -4 |
| 9 | -7 |
| 10 | 3 |
| 11 | -1 |
| 12 | 5 |
| 13 | 9 |
| 14 | -4 |
| 15 | 1 |
| 16 | -12 |
| 17 | -23 |
| 18 | 11 |
| 19 | -1 |
| 20 | 13 |
| 21 | 25 |
| 22 | -12 |
| 23 | 1 |
| 24 | -16 |
| 25 | -31 |
| 26 | 15 |
| 27 | -1 |
| 28 | 17 |
| 29 | 33 |
| 30 | -16 |
| 31 | 1 |
| 32 | -32 |
| 33 | -63 |
| 34 | 31 |
| 35 | -1 |
| 36 | 33 |
| 37 | 65 |
| 38 | -32 |
| 39 | 1 |
| 40 | -36 |
| 41 | -71 |
| 42 | 35 |
| 43 | -1 |
| 44 | 37 |
| 45 | 73 |
| 46 | -36 |
| 47 | 1 |
| 48 | -44 |
| 49 | -87 |
| 50 | 43 |
| 51 | -1 |
| 52 | 45 |
| 53 | 89 |
| 54 | -44 |
| 55 | 1 |
| 56 | -48 |
| 57 | -95 |
| 58 | 47 |
| 59 | -1 |
| 60 | 49 |
| 61 | 97 |
| 62 | -48 |
| 63 | 1 |
| 64 | -80 |
| 65 | -159 |
| 66 | 79 |
| 67 | -1 |
| 68 | 81 |
| 69 | 161 |
| 70 | -80 |
| 71 | 1 |
| 72 | -84 |
| 73 | -167 |
| 74 | 83 |
| 75 | -1 |
| 76 | 85 |
| 77 | 169 |
| 78 | -84 |
| 79 | 1 |
| 80 | -92 |