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 | 4 |
| 4 | 68 |
| 5 | 376 |
| 6 | 1440 |
| 7 | 4736 |
| 8 | 14272 |
| 9 | 40576 |
| 10 | 110592 |
| 11 | 291840 |
| 12 | 750592 |
| 13 | 1890304 |
| 14 | 4677632 |
| 15 | 11403264 |
| 16 | 27443200 |
| 17 | 65306624 |
| 18 | 153878528 |
| 19 | 359399424 |
| 20 | 832831488 |
| 21 | 1916272640 |
| 22 | 4380950528 |
| 23 | 9957277696 |
| 24 | 22510829568 |
| 25 | 50642026496 |
| 26 | 113413980160 |