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 | -1 |
| 6 | 5 |
| 7 | -3 |
| 8 | -1 |
| 9 | -1 |
| 10 | 7 |
| 11 | -5 |
| 12 | -3 |
| 13 | -1 |
| 14 | -1 |
| 15 | 11 |
| 16 | -7 |
| 17 | -5 |
| 18 | -3 |
| 19 | -1 |
| 20 | -1 |
| 21 | 13 |
| 22 | -11 |
| 23 | -7 |
| 24 | -5 |
| 25 | -3 |
| 26 | -1 |
| 27 | -1 |
| 28 | 17 |
| 29 | -13 |
| 30 | -11 |
| 31 | -7 |
| 32 | -5 |
| 33 | -3 |
| 34 | -1 |
| 35 | -1 |
| 36 | 19 |
| 37 | -17 |
| 38 | -13 |
| 39 | -11 |
| 40 | -7 |
| 41 | -5 |
| 42 | -3 |
| 43 | -1 |
| 44 | -1 |
| 45 | 23 |
| 46 | -19 |
| 47 | -17 |
| 48 | -13 |
| 49 | -11 |
| 50 | -7 |
| 51 | -5 |
| 52 | -3 |
| 53 | -1 |
| 54 | -1 |
| 55 | 29 |
| 56 | -23 |
| 57 | -19 |
| 58 | -17 |
| 59 | -13 |
| 60 | -11 |
| 61 | -7 |
| 62 | -5 |
| 63 | -3 |
| 64 | -1 |
| 65 | -1 |