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 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 9 |
| 5 | 21 |
| 6 | 65 |
| 7 | 215 |
| 8 | 713 |
| 9 | 2809 |
| 10 | 11425 |
| 11 | 49339 |
| 12 | 234825 |
| 13 | 1148013 |
| 14 | 6009153 |
| 15 | 33216239 |
| 16 | 190115849 |
| 17 | 1152491825 |
| 18 | 7244099617 |
| 19 | 47387741107 |
| 20 | 323632894729 |
| 21 | 2280785100549 |
| 22 | 16702573959489 |
| 23 | 126413562204231 |
| 24 | 986688266888777 |