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 | 0 |
| 2 | 0 |
| 3 | -1 |
| 4 | 0 |
| 5 | 1 |
| 6 | 10 |
| 7 | -1 |
| 8 | -56 |
| 9 | -279 |
| 10 | 246 |
| 11 | 4619 |
| 12 | 14388 |
| 13 | -53195 |
| 14 | -556478 |
| 15 | -864865 |
| 16 | 13276912 |
| 17 | 90192753 |
| 18 | -72903378 |
| 19 | -3987888493 |
| 20 | -16957067028 |
| 21 | 101506932205 |
| 22 | 1411655530330 |
| 23 | 2206092853799 |
| 24 | -70455418153496 |
| 25 | -549095655588183 |
| 26 | 1428569363164230 |