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 | 1 |
| 3 | 5 |
| 4 | 22 |
| 5 | 90 |
| 6 | 363 |
| 7 | 1455 |
| 8 | 5824 |
| 9 | 23300 |
| 10 | 93205 |
| 11 | 372825 |
| 12 | 1491306 |
| 13 | 5965230 |
| 14 | 23860927 |
| 15 | 95443715 |
| 16 | 381774868 |
| 17 | 1527099480 |
| 18 | 6108397929 |
| 19 | 24433591725 |
| 20 | 97734366910 |
| 21 | 390937467650 |
| 22 | 1563749870611 |
| 23 | 6254999482455 |
| 24 | 25019997929832 |