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) |
|---|---|
| 2 | 1 |
| 3 | 3 |
| 4 | 14 |
| 5 | 65 |
| 6 | 251 |
| 7 | 1288 |
| 8 | 4830 |
| 9 | 25518 |
| 10 | 95388 |
| 11 | 510532 |
| 12 | 1910821 |
| 13 | 10309234 |
| 14 | 38656462 |
| 15 | 209766714 |
| 16 | 787912030 |
| 17 | 4294635438 |
| 18 | 16155375825 |
| 19 | 88371236851 |
| 20 | 332859949946 |
| 21 | 1826080683788 |
| 22 | 6885797551334 |
| 23 | 37867515477338 |
| 24 | 142929375411104 |
| 25 | 787637258527505 |
| 26 | 2975423924172735 |
| 27 | 16425495119248041 |
| 28 | 62096233990615140 |
| 29 | 343318987947145114 |