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) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 3 |
| 5 | 24 |
| 6 | 133 |
| 7 | 635 |
| 8 | 2807 |
| 9 | 11864 |
| 10 | 48756 |
| 11 | 196707 |
| 12 | 783750 |
| 13 | 3095708 |
| 14 | 12152855 |
| 15 | 47500635 |
| 16 | 185082495 |
| 17 | 719559600 |
| 18 | 2793121080 |
| 19 | 10830450780 |
| 20 | 41965864794 |
| 21 | 162539516448 |
| 22 | 629399492330 |
| 23 | 2437072038302 |
| 24 | 9437097796918 |