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) |
|---|---|
| 1 | 1 |
| 2 | -2 |
| 3 | 15 |
| 4 | -594 |
| 5 | -5187 |
| 6 | 23244 |
| 7 | 122475 |
| 8 | -279292 |
| 9 | -1157143 |
| 10 | 1850930 |
| 11 | 6642839 |
| 12 | -8529278 |
| 13 | -27810555 |
| 14 | 30741424 |
| 15 | 93575187 |
| 16 | -92784984 |
| 17 | -268191855 |
| 18 | 244875462 |
| 19 | 679807583 |
| 20 | -581798410 |
| 21 | -1563707379 |
| 22 | 1270245108 |
| 23 | 3324627195 |
| 24 | -2587197204 |
| 25 | -6623079687 |
| 26 | 4972012474 |
| 27 | 12491212135 |