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) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 6 |
| 4 | 15 |
| 5 | 64 |
| 6 | 153 |
| 7 | 638 |
| 8 | 1519 |
| 9 | 6320 |
| 10 | 15041 |
| 11 | 62566 |
| 12 | 148895 |
| 13 | 619344 |
| 14 | 1473913 |
| 15 | 6130878 |
| 16 | 14590239 |
| 17 | 60689440 |
| 18 | 144428481 |
| 19 | 600763526 |
| 20 | 1429694575 |
| 21 | 5946945824 |
| 22 | 14152517273 |
| 23 | 58868694718 |
| 24 | 140095478159 |
| 25 | 582740001360 |
| 26 | 1386802264321 |
| 27 | 5768531318886 |
| 28 | 13727927165055 |