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) |
|---|---|
| 2 | 0 |
| 3 | 1 |
| 4 | 3 |
| 5 | 12 |
| 6 | 50 |
| 7 | 27 |
| 8 | 1323 |
| 9 | -928 |
| 10 | 1080 |
| 11 | -48525 |
| 12 | -3237113 |
| 13 | -7587864 |
| 14 | -31268252574 |
| 15 | -770720657 |
| 16 | -232936065 |
| 17 | -179731134720 |
| 18 | -542023437008852 |
| 19 | -3212744374395 |
| 20 | -926840515700222955 |
| 21 | -389358194177500 |
| 22 | -17858352159793110 |