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 | 10 |
| 3 | 42 |
| 4 | 90 |
| 5 | 2448 |
| 6 | 4680 |
| 7 | 27144 |
| 8 | 117000 |
| 9 | 154498509 |
| 10 | 222970077 |
| 11 | 11049088050 |
| 12 | 63554826816 |