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 | 0 |
| 3 | -1 |
| 4 | 0 |
| 5 | -1 |
| 6 | 1 |
| 7 | -1 |
| 8 | 3 |
| 9 | -1 |
| 10 | 5 |
| 11 | -2 |
| 12 | 7 |
| 13 | -7 |
| 14 | 9 |
| 15 | -16 |
| 16 | 11 |
| 17 | -29 |
| 18 | 20 |
| 19 | -46 |
| 20 | 45 |
| 21 | -66 |
| 22 | 94 |
| 23 | -95 |
| 24 | 175 |
| 25 | -161 |
| 26 | 294 |
| 27 | -307 |
| 28 | 458 |
| 29 | -594 |
| 30 | 715 |
| 31 | -1096 |
| 32 | 1193 |
| 33 | -1891 |
| 34 | 2132 |
| 35 | -3106 |
| 36 | 3916 |
| 37 | -5063 |
| 38 | 7083 |
| 39 | -8484 |
| 40 | 12347 |
| 41 | -14770 |
| 42 | 20867 |
| 43 | -26310 |
| 44 | 34898 |
| 45 | -46771 |
| 46 | 58967 |
| 47 | -81665 |
| 48 | 101680 |
| 49 | -139951 |
| 50 | 178094 |
| 51 | -237620 |