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 | -6 |
| 4 | 10 |
| 5 | -16 |
| 6 | 24 |
| 7 | -36 |
| 8 | 52 |
| 9 | -74 |
| 10 | 104 |
| 11 | -144 |
| 12 | 198 |
| 13 | -268 |
| 14 | 360 |
| 15 | -480 |
| 16 | 634 |
| 17 | -832 |
| 18 | 1084 |
| 19 | -1404 |
| 20 | 1808 |
| 21 | -2316 |
| 22 | 2952 |
| 23 | -3744 |
| 24 | 4728 |
| 25 | -5946 |
| 26 | 7448 |
| 27 | -9294 |
| 28 | 11556 |
| 29 | -14320 |
| 30 | 17688 |
| 31 | -21780 |
| 32 | 26740 |
| 33 | -32736 |
| 34 | 39968 |
| 35 | -48672 |
| 36 | 59122 |
| 37 | -71644 |
| 38 | 86616 |
| 39 | -104484 |
| 40 | 125768 |
| 41 | -151072 |