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 | 0 |
| 4 | 35 |
| 5 | -76 |
| 6 | 35 |
| 7 | -155 |
| 8 | 455 |
| 9 | -720 |
| 10 | 1369 |
| 11 | -1935 |
| 12 | 4415 |
| 13 | -10405 |
| 14 | 12990 |
| 15 | -22512 |
| 16 | 54405 |
| 17 | -92480 |
| 18 | 143150 |
| 19 | -253015 |
| 20 | 488512 |
| 21 | -859795 |
| 22 | 1377670 |
| 23 | -2332365 |
| 24 | 4276230 |
| 25 | -7666511 |
| 26 | 12092880 |
| 27 | -19796225 |
| 28 | 36845455 |
| 29 | -62053775 |