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 | -3 |
| 4 | 7 |
| 5 | -11 |
| 6 | 17 |
| 7 | -21 |
| 8 | 35 |
| 9 | -67 |
| 10 | 125 |
| 11 | -179 |
| 12 | 246 |
| 13 | -384 |
| 14 | 715 |
| 15 | -1199 |
| 16 | 1871 |
| 17 | -2850 |
| 18 | 4593 |
| 19 | -7589 |
| 20 | 12811 |
| 21 | -20366 |
| 22 | 31545 |
| 23 | -50483 |
| 24 | 84597 |
| 25 | -138964 |
| 26 | 222534 |
| 27 | -352910 |
| 28 | 569680 |
| 29 | -931694 |
| 30 | 1523165 |
| 31 | -2451150 |
| 32 | 3924137 |
| 33 | -6331780 |
| 34 | 10329289 |
| 35 | -16804843 |
| 36 | 27109912 |
| 37 | -43594466 |
| 38 | 70485938 |
| 39 | -114450985 |
| 40 | 185713588 |
| 41 | -300089184 |
| 42 | 484106880 |
| 43 | -782672321 |
| 44 | 1269075821 |
| 45 | -2056723036 |
| 46 | 3325362211 |
| 47 | -5371243069 |
| 48 | 8688055226 |