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 | 3 |
| 3 | 8 |
| 4 | 24 |
| 5 | 74 |
| 6 | 245 |
| 7 | 815 |
| 8 | 2796 |
| 9 | 9707 |
| 10 | 34186 |
| 11 | 121562 |
| 12 | 436298 |
| 13 | 1577310 |
| 14 | 5740299 |
| 15 | 21008777 |
| 16 | 77279892 |
| 17 | 285544700 |
| 18 | 1059332082 |
| 19 | 3944254118 |
| 20 | 14734260864 |
| 21 | 55207053787 |
| 22 | 207421476390 |
| 23 | 781283558998 |
| 24 | 2949675307082 |
| 25 | 11160264942376 |
| 26 | 42309912978708 |
| 27 | 160700303600030 |