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 | -4 |
| 2 | 12 |
| 3 | -32 |
| 4 | 80 |
| 5 | -184 |
| 6 | 400 |
| 7 | -832 |
| 8 | 1664 |
| 9 | -3220 |
| 10 | 6056 |
| 11 | -11104 |
| 12 | 19904 |
| 13 | -34968 |
| 14 | 60320 |
| 15 | -102336 |
| 16 | 171008 |
| 17 | -281800 |
| 18 | 458428 |
| 19 | -736928 |
| 20 | 1171552 |
| 21 | -1843328 |
| 22 | 2872368 |
| 23 | -4435392 |
| 24 | 6790656 |
| 25 | -10313180 |
| 26 | 15544136 |
| 27 | -23259968 |
| 28 | 34568576 |
| 29 | -51042392 |
| 30 | 74901984 |
| 31 | -109268224 |
| 32 | 158507008 |