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 | 3 |
| 2 | 7 |
| 3 | 24 |
| 4 | 76 |
| 5 | 272 |
| 6 | 948 |
| 7 | 3496 |
| 8 | 12920 |
| 9 | 48792 |
| 10 | 185912 |
| 11 | 716472 |
| 12 | 2781600 |
| 13 | 10878640 |
| 14 | 42789292 |
| 15 | 169181280 |
| 16 | 671865840 |
| 17 | 2678679360 |
| 18 | 10716650484 |
| 19 | 43007271768 |
| 20 | 173072547360 |
| 21 | 698235684336 |
| 22 | 2823329204964 |
| 23 | 11439823954664 |
| 24 | 46440709197120 |
| 25 | 188856966713360 |
| 26 | 769241291697640 |
| 27 | 3137871076653336 |
| 28 | 12817512478814400 |