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 | 4 |
| 2 | 9 |
| 3 | 12 |
| 4 | -1 |
| 5 | -56 |
| 6 | -178 |
| 7 | -336 |
| 8 | -321 |
| 9 | 412 |
| 10 | 2729 |
| 11 | 7084 |
| 12 | 11202 |
| 13 | 5724 |
| 14 | -29911 |
| 15 | -121988 |
| 16 | -266881 |
| 17 | -338976 |
| 18 | 54222 |
| 19 | 1644184 |
| 20 | 5108159 |
| 21 | 9479212 |
| 22 | 8682249 |
| 23 | -12837036 |
| 24 | -79315198 |
| 25 | -202151756 |
| 26 | -313431031 |
| 27 | -143085588 |
| 28 | 892383039 |