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 | 3 |
| 1 | -4 |
| 2 | 10 |
| 3 | -25 |
| 4 | 66 |
| 5 | -179 |
| 6 | 493 |
| 7 | -1369 |
| 8 | 3818 |
| 9 | -10672 |
| 10 | 29865 |
| 11 | -83626 |
| 12 | 234237 |
| 13 | -656205 |
| 14 | 1838483 |
| 15 | -5151080 |
| 16 | 14432666 |
| 17 | -40438941 |
| 18 | 113306686 |
| 19 | -317477255 |
| 20 | 889550021 |
| 21 | -2492461633 |
| 22 | 6983719214 |
| 23 | -19567941936 |
| 24 | 54828148469 |
| 25 | -153625048854 |
| 26 | 430447808073 |
| 27 | -1206087937261 |
| 28 | 3379383275971 |
| 29 | -9468821484028 |