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 | 3 |
| 2 | 9 |
| 3 | 25 |
| 4 | 66 |
| 5 | 168 |
| 6 | 416 |
| 7 | 1008 |
| 8 | 2400 |
| 9 | 5632 |
| 10 | 13056 |
| 11 | 29952 |
| 12 | 68096 |
| 13 | 153600 |
| 14 | 344064 |
| 15 | 765952 |
| 16 | 1695744 |
| 17 | 3735552 |
| 18 | 8192000 |
| 19 | 17891328 |
| 20 | 38928384 |
| 21 | 84410368 |
| 22 | 182452224 |
| 23 | 393216000 |
| 24 | 845152256 |
| 25 | 1811939328 |
| 26 | 3875536896 |
| 27 | 8271167488 |
| 28 | 17616076800 |