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 | 3 |
| 2 | 12 |
| 3 | 50 |
| 4 | 212 |
| 5 | 905 |
| 6 | 3872 |
| 7 | 16576 |
| 8 | 70968 |
| 9 | 303832 |
| 10 | 1300737 |
| 11 | 5568473 |
| 12 | 23838453 |
| 13 | 102051167 |
| 14 | 436874885 |
| 15 | 1870233780 |
| 16 | 8006350999 |
| 17 | 34274673894 |
| 18 | 146727674181 |
| 19 | 628131735844 |
| 20 | 2688991567300 |
| 21 | 11511399994065 |
| 22 | 49279563214531 |