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 | 2 |
| 3 | -4 |
| 4 | 10 |
| 5 | -16 |
| 6 | 20 |
| 7 | -32 |
| 8 | 58 |
| 9 | -86 |
| 10 | 112 |
| 11 | -164 |
| 12 | 260 |
| 13 | -368 |
| 14 | 480 |
| 15 | -672 |
| 16 | 986 |
| 17 | -1348 |
| 18 | 1750 |
| 19 | -2372 |
| 20 | 3312 |
| 21 | -4416 |
| 22 | 5684 |
| 23 | -7520 |
| 24 | 10148 |
| 25 | -13266 |
| 26 | 16912 |
| 27 | -21960 |
| 28 | 28896 |
| 29 | -37168 |
| 30 | 46944 |
| 31 | -60032 |
| 32 | 77466 |
| 33 | -98312 |
| 34 | 123076 |
| 35 | -155392 |
| 36 | 197422 |
| 37 | -247696 |
| 38 | 307540 |
| 39 | -384096 |
| 40 | 481776 |
| 41 | -598500 |