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 | -2 |
| 2 | 3 |
| 3 | -6 |
| 4 | 11 |
| 5 | -18 |
| 6 | 28 |
| 7 | -44 |
| 8 | 69 |
| 9 | -104 |
| 10 | 152 |
| 11 | -222 |
| 12 | 323 |
| 13 | -460 |
| 14 | 645 |
| 15 | -902 |
| 16 | 1254 |
| 17 | -1722 |
| 18 | 2343 |
| 19 | -3174 |
| 20 | 4278 |
| 21 | -5722 |
| 22 | 7601 |
| 23 | -10056 |
| 24 | 13250 |
| 25 | -17358 |
| 26 | 22623 |
| 27 | -29382 |
| 28 | 38021 |
| 29 | -48984 |
| 30 | 62857 |
| 31 | -80404 |
| 32 | 102528 |
| 33 | -130282 |
| 34 | 165002 |
| 35 | -208398 |
| 36 | 262495 |
| 37 | -329666 |
| 38 | 412878 |
| 39 | -515840 |
| 40 | 642941 |
| 41 | -799362 |
| 42 | 991478 |