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 | 0 |
| 1 | -1 |
| 2 | 7 |
| 3 | -19 |
| 4 | 41 |
| 5 | -74 |
| 6 | 122 |
| 7 | -186 |
| 8 | 270 |
| 9 | -375 |
| 10 | 505 |
| 11 | -661 |
| 12 | 847 |
| 13 | -1064 |
| 14 | 1316 |
| 15 | -1604 |
| 16 | 1932 |
| 17 | -2301 |
| 18 | 2715 |
| 19 | -3175 |
| 20 | 3685 |
| 21 | -4246 |
| 22 | 4862 |
| 23 | -5534 |
| 24 | 6266 |
| 25 | -7059 |
| 26 | 7917 |
| 27 | -8841 |
| 28 | 9835 |
| 29 | -10900 |
| 30 | 12040 |
| 31 | -13256 |
| 32 | 14552 |
| 33 | -15929 |
| 34 | 17391 |
| 35 | -18939 |
| 36 | 20577 |
| 37 | -22306 |
| 38 | 24130 |
| 39 | -26050 |
| 40 | 28070 |