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 | 6 |
| 2 | -79 |
| 3 | -1844 |
| 4 | -13983 |
| 5 | -61318 |
| 6 | -162287 |
| 7 | 0 |
| 8 | 3667649 |
| 9 | 35570638 |
| 10 | 272475249 |
| 11 | 1957839572 |
| 12 | 13805455393 |
| 13 | 96826261890 |
| 14 | 678117659345 |
| 15 | 4747390650568 |
| 16 | 33232662134145 |
| 17 | 232630103648534 |
| 18 | 1628412985690417 |
| 19 | 11398894291501404 |
| 20 | 79792265017612001 |
| 21 | 558545862282195466 |