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) |
|---|---|
| 4 | 1 |
| 5 | 5 |
| 6 | 23 |
| 7 | 115 |
| 8 | 668 |
| 9 | 3401 |
| 10 | 16469 |
| 11 | 74410 |
| 12 | 317612 |
| 13 | 1287147 |
| 14 | 5015932 |
| 15 | 18920467 |
| 16 | 69496943 |
| 17 | 249618639 |
| 18 | 879998839 |
| 19 | 3053446651 |
| 20 | 10452089459 |
| 21 | 35360685297 |
| 22 | 118416973230 |
| 23 | 393038044024 |
| 24 | 1294335897888 |
| 25 | 4232938101229 |
| 26 | 13757913332396 |