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 | 5 |
| 3 | 24 |
| 4 | 81 |
| 5 | 198 |
| 6 | 542 |
| 7 | 1550 |
| 8 | 4497 |
| 9 | 12732 |
| 10 | 36210 |
| 11 | 103579 |
| 12 | 296250 |
| 13 | 846303 |
| 14 | 2417308 |
| 15 | 6907329 |
| 16 | 19737889 |
| 17 | 56396602 |
| 18 | 161138306 |
| 19 | 460420182 |
| 20 | 1315565326 |
| 21 | 3758963099 |
| 22 | 10740463167 |
| 23 | 30688703123 |
| 24 | 87686813826 |
| 25 | 250547405698 |
| 26 | 715888629071 |
| 27 | 2045507376543 |
| 28 | 5844625042904 |