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 | -28 |
| 2 | 378 |
| 3 | -3304 |
| 4 | 21259 |
| 5 | -108892 |
| 6 | 469630 |
| 7 | -1778536 |
| 8 | 6096125 |
| 9 | -19303088 |
| 10 | 57249374 |
| 11 | -160633424 |
| 12 | 429762354 |
| 13 | -1103189388 |
| 14 | 2730461208 |
| 15 | -6542033848 |
| 16 | 15223719392 |
| 17 | -34504452668 |
| 18 | 76349114366 |
| 19 | -165267288816 |
| 20 | 350579820199 |
| 21 | -729912979244 |
| 22 | 1493568080228 |
| 23 | -3007227042624 |
| 24 | 5964244118126 |