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 | 6 |
| 3 | 12 |
| 4 | 24 |
| 5 | 54 |
| 6 | 186 |
| 7 | 3246 |
| 8 | 25926 |
| 9 | 169314 |
| 10 | 412026 |
| 11 | 541524 |
| 12 | 37949286 |
| 13 | 124716066 |
| 14 | 324532464 |
| 15 | 26678398374 |
| 16 | 3559613215806 |
| 17 | 30751771983294 |
| 18 | 20116294396883346 |