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 | 0 |
| 2 | 1 |
| 3 | 3 |
| 4 | 11 |
| 5 | 42 |
| 6 | 167 |
| 7 | 684 |
| 8 | 2867 |
| 9 | 12240 |
| 10 | 53043 |
| 11 | 232731 |
| 12 | 1031829 |
| 13 | 4615542 |
| 14 | 20805081 |
| 15 | 94410363 |
| 16 | 430945739 |
| 17 | 1977366192 |
| 18 | 9115261211 |
| 19 | 42195093993 |
| 20 | 196060049129 |
| 21 | 914110333422 |
| 22 | 4275222950221 |
| 23 | 20051858039718 |
| 24 | 94294269673861 |