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 | 4 |
| 3 | -8 |
| 4 | 14 |
| 5 | -22 |
| 6 | 36 |
| 7 | -56 |
| 8 | 84 |
| 9 | -126 |
| 10 | 184 |
| 11 | -264 |
| 12 | 376 |
| 13 | -528 |
| 14 | 732 |
| 15 | -1008 |
| 16 | 1374 |
| 17 | -1856 |
| 18 | 2492 |
| 19 | -3320 |
| 20 | 4394 |
| 21 | -5784 |
| 22 | 7568 |
| 23 | -9848 |
| 24 | 12756 |
| 25 | -16442 |
| 26 | 21096 |
| 27 | -26960 |
| 28 | 34312 |
| 29 | -43500 |
| 30 | 54956 |
| 31 | -69184 |
| 32 | 86804 |
| 33 | -108576 |
| 34 | 135392 |
| 35 | -168336 |
| 36 | 208722 |
| 37 | -258096 |
| 38 | 318320 |
| 39 | -391632 |