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 | 12 |
| 3 | 48 |
| 4 | 144 |
| 5 | 440 |
| 6 | 1816 |
| 7 | 6816 |
| 8 | 25816 |
| 9 | 101856 |
| 10 | 397944 |
| 11 | 1573464 |
| 12 | 6274560 |
| 13 | 25071152 |
| 14 | 100180872 |
| 15 | 400625360 |