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 | 2 |
| 4 | -2 |
| 5 | 0 |
| 6 | 4 |
| 7 | -4 |
| 8 | -2 |
| 9 | 6 |
| 10 | -4 |
| 11 | -2 |
| 12 | 10 |
| 13 | -8 |
| 14 | -6 |
| 15 | 14 |
| 16 | -10 |
| 17 | -4 |
| 18 | 20 |
| 19 | -16 |
| 20 | -8 |
| 21 | 24 |
| 22 | -18 |
| 23 | -6 |
| 24 | 34 |
| 25 | -28 |
| 26 | -14 |
| 27 | 42 |
| 28 | -34 |
| 29 | -8 |
| 30 | 56 |
| 31 | -48 |
| 32 | -18 |
| 33 | 66 |
| 34 | -52 |
| 35 | -14 |
| 36 | 86 |
| 37 | -72 |
| 38 | -30 |
| 39 | 102 |
| 40 | -80 |
| 41 | -22 |
| 42 | 126 |
| 43 | -104 |
| 44 | -40 |
| 45 | 144 |
| 46 | -110 |
| 47 | -34 |
| 48 | 178 |
| 49 | -144 |
| 50 | -62 |
| 51 | 206 |
| 52 | -158 |
| 53 | -48 |
| 54 | 248 |
| 55 | -200 |
| 56 | -82 |
| 57 | 282 |
| 58 | -208 |
| 59 | -74 |
| 60 | 338 |
| 61 | -264 |
| 62 | -122 |
| 63 | 386 |
| 64 | -282 |
| 65 | -104 |
| 66 | 452 |
| 67 | -348 |
| 68 | -156 |
| 69 | 504 |