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 | -13 |
| 2 | 229 |
| 3 | -195 |
| 4 | 24599 |
| 5 | -2665 |
| 6 | 46507 |
| 7 | -44915 |
| 8 | 8833199 |
| 9 | 416403 |
| 10 | -1179453655 |
| 11 | -118121575 |
| 12 | 1236316425587 |
| 13 | 21956821471 |
| 14 | -4276025257877 |
| 15 | -5737064850075 |
| 16 | 108297641842213183 |
| 17 | 1936750565168939 |
| 18 | -9194148370010304671 |
| 19 | -822132445349796815 |
| 20 | 12552825320814878738389 |