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 | 3 |
| 3 | -5 |
| 4 | 10 |
| 5 | -15 |
| 6 | 26 |
| 7 | -39 |
| 8 | 63 |
| 9 | -92 |
| 10 | 140 |
| 11 | -201 |
| 12 | 295 |
| 13 | -415 |
| 14 | 591 |
| 15 | -818 |
| 16 | 1140 |
| 17 | -1554 |
| 18 | 2126 |
| 19 | -2861 |
| 20 | 3855 |
| 21 | -5126 |
| 22 | 6816 |
| 23 | -8970 |
| 24 | 11793 |
| 25 | -15372 |
| 26 | 20007 |
| 27 | -25857 |
| 28 | 33356 |
| 29 | -42771 |
| 30 | 54734 |
| 31 | -69683 |
| 32 | 88530 |
| 33 | -111968 |
| 34 | 141312 |
| 35 | -177642 |
| 36 | 222842 |
| 37 | -278557 |
| 38 | 347484 |
| 39 | -432095 |
| 40 | 536230 |