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 | 1 |
| 1 | 1 |
| 2 | 7 |
| 3 | 28 |
| 4 | 140 |
| 5 | 602 |
| 6 | 2772 |
| 7 | 12166 |
| 8 | 54046 |
| 9 | 236093 |
| 10 | 1030101 |
| 11 | 4458247 |
| 12 | 19223202 |
| 13 | 82448782 |
| 14 | 352247250 |
| 15 | 1498724840 |
| 16 | 6353940527 |
| 17 | 26844401919 |
| 18 | 113051495750 |
| 19 | 474652297902 |
| 20 | 1987159118837 |
| 21 | 8296760311018 |
| 22 | 34551340915438 |
| 23 | 143533939056129 |
| 24 | 594877730354756 |