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 | 5 |
| 2 | 5 |
| 3 | -35 |
| 4 | -140 |
| 5 | -84 |
| 6 | 840 |
| 7 | 2640 |
| 8 | 495 |
| 9 | -16445 |
| 10 | -41041 |
| 11 | 11375 |
| 12 | 282100 |
| 13 | 559300 |
| 14 | -474300 |
| 15 | -4399260 |
| 16 | -6807225 |
| 17 | 11062275 |
| 18 | 63677075 |
| 19 | 73363675 |
| 20 | -208411280 |
| 21 | -865816600 |
| 22 | -665544100 |
| 23 | 3475847700 |
| 24 | 11129861925 |
| 25 | 4130560161 |
| 26 | -53332660395 |
| 27 | -135538728395 |
| 28 | 9634906640 |