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) |
|---|---|
| 1 | 3 |
| 2 | -3 |
| 3 | 8 |
| 4 | -21 |
| 5 | 48 |
| 6 | -116 |
| 7 | 312 |
| 8 | -831 |
| 9 | 2184 |
| 10 | -5880 |
| 11 | 16104 |
| 12 | -44336 |
| 13 | 122640 |
| 14 | -341484 |
| 15 | 956576 |
| 16 | -2690841 |
| 17 | 7596480 |
| 18 | -21522228 |
| 19 | 61171656 |
| 20 | -174342144 |
| 21 | 498111952 |
| 22 | -1426403748 |
| 23 | 4093181688 |
| 24 | -11767919276 |
| 25 | 33891544368 |
| 26 | -97764009000 |