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 | -1 |
| 4 | 2 |
| 5 | -1 |
| 6 | 4 |
| 7 | -5 |
| 8 | 7 |
| 9 | -8 |
| 10 | 10 |
| 11 | -15 |
| 12 | 18 |
| 13 | -22 |
| 14 | 26 |
| 15 | -37 |
| 16 | 46 |
| 17 | -53 |
| 18 | 66 |
| 19 | -84 |
| 20 | 104 |
| 21 | -122 |
| 22 | 148 |
| 23 | -183 |
| 24 | 224 |
| 25 | -263 |
| 26 | 312 |
| 27 | -379 |
| 28 | 454 |
| 29 | -531 |
| 30 | 626 |
| 31 | -750 |
| 32 | 887 |
| 33 | -1034 |
| 34 | 1208 |
| 35 | -1428 |
| 36 | 1672 |
| 37 | -1936 |
| 38 | 2250 |
| 39 | -2633 |
| 40 | 3062 |
| 41 | -3529 |
| 42 | 4076 |
| 43 | -4728 |
| 44 | 5460 |
| 45 | -6264 |
| 46 | 7196 |
| 47 | -8290 |
| 48 | 9520 |
| 49 | -10875 |
| 50 | 12431 |
| 51 | -14238 |