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) |
|---|---|
| 1 | 4 |
| 2 | 28 |
| 3 | 1860 |
| 4 | 149052 |
| 5 | 12771496 |
| 6 | 1221908916 |
| 7 | 132662942122 |
| 8 | 16354869261256 |
| 9 | 2272946910544740 |
| 10 | 353076161059625536 |
| 11 | 60799066209732571716 |
| 12 | 11518836088596729968092 |