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 | 18 |
| 5 | 65 |
| 6 | 346 |
| 7 | 1288 |
| 8 | 6818 |
| 9 | 25518 |
| 10 | 136152 |
| 11 | 510532 |
| 12 | 2745347 |
| 13 | 10309234 |
| 14 | 55784794 |
| 15 | 209766714 |
| 16 | 1140670242 |
| 17 | 4294635438 |
| 18 | 23445204441 |