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) |
|---|---|
| 8 | 1 |
| 9 | 4 |
| 10 | 28 |
| 11 | 137 |
| 12 | 751 |
| 13 | 3797 |
| 14 | 19868 |
| 15 | 103169 |
| 16 | 544446 |
| 17 | 2892654 |
| 18 | 15609326 |
| 19 | 85185225 |
| 20 | 471914661 |
| 21 | 2647616529 |
| 22 | 15072126865 |
| 23 | 86928421109 |
| 24 | 508477806633 |
| 25 | 3013152898489 |
| 26 | 18098553323837 |
| 27 | 110098999926894 |
| 28 | 678500886312946 |
| 29 | 4233264326440478 |
| 30 | 26741870913391272 |