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) |
|---|---|
| 3 | 1 |
| 4 | 6 |
| 5 | 34 |
| 6 | 192 |
| 7 | 1134 |
| 8 | 6716 |
| 9 | 40872 |
| 10 | 255308 |
| 11 | 1646736 |
| 12 | 10966948 |
| 13 | 75443030 |
| 14 | 534853224 |
| 15 | 3896868930 |
| 16 | 29123747126 |
| 17 | 222952505194 |
| 18 | 1746931730522 |
| 19 | 14000986111688 |
| 20 | 114736915809792 |
| 21 | 960962428696876 |
| 22 | 8221685556988910 |
| 23 | 71811228291496646 |
| 24 | 639892151737631798 |