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 | -1 |
| 5 | 2 |
| 6 | 0 |
| 7 | 1 |
| 8 | -2 |
| 9 | 5 |
| 10 | -5 |
| 11 | 4 |
| 12 | -6 |
| 13 | 18 |
| 14 | -30 |
| 15 | 35 |
| 16 | -43 |
| 17 | 84 |
| 18 | -167 |
| 19 | 261 |
| 20 | -352 |
| 21 | 545 |
| 22 | -1010 |
| 23 | 1790 |
| 24 | -2783 |
| 25 | 4207 |
| 26 | -7025 |
| 27 | 12464 |
| 28 | -21071 |
| 29 | 33567 |
| 30 | -54154 |
| 31 | 92317 |
| 32 | -159366 |
| 33 | 266150 |
| 34 | -435285 |
| 35 | 725260 |
| 36 | -1239404 |
| 37 | 2112351 |
| 38 | -3535532 |
| 39 | 5894852 |
| 40 | -9964767 |
| 41 | 17008752 |
| 42 | -28880694 |
| 43 | 48645873 |