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 | 2 |
| 3 | -2 |
| 4 | 2 |
| 5 | -3 |
| 6 | 4 |
| 7 | -4 |
| 8 | 5 |
| 9 | -6 |
| 10 | 6 |
| 11 | -8 |
| 12 | 10 |
| 13 | -10 |
| 14 | 12 |
| 15 | -14 |
| 16 | 15 |
| 17 | -18 |
| 18 | 20 |
| 19 | -22 |
| 20 | 26 |
| 21 | -29 |
| 22 | 32 |
| 23 | -36 |
| 24 | 40 |
| 25 | -44 |
| 26 | 50 |
| 27 | -56 |
| 28 | 60 |
| 29 | -68 |
| 30 | 76 |
| 31 | -82 |
| 32 | 92 |
| 33 | -101 |
| 34 | 110 |
| 35 | -122 |
| 36 | 134 |
| 37 | -146 |
| 38 | 160 |
| 39 | -176 |
| 40 | 191 |
| 41 | -210 |
| 42 | 230 |
| 43 | -248 |
| 44 | 272 |
| 45 | -296 |
| 46 | 320 |
| 47 | -350 |
| 48 | 380 |
| 49 | -410 |
| 50 | 446 |
| 51 | -484 |
| 52 | 522 |
| 53 | -566 |
| 54 | 612 |
| 55 | -660 |
| 56 | 715 |
| 57 | -772 |
| 58 | 830 |
| 59 | -896 |
| 60 | 966 |
| 61 | -1038 |