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 | 16 |
| 3 | 60 |
| 4 | 208 |
| 5 | 680 |
| 6 | 2136 |
| 7 | 6524 |
| 8 | 19520 |
| 9 | 57492 |
| 10 | 167240 |
| 11 | 481624 |
| 12 | 1375536 |