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 | 0 |
| 1 | 4 |
| 2 | 36 |
| 3 | 292 |
| 4 | 2340 |
| 5 | 18724 |
| 6 | 149796 |
| 7 | 1198372 |
| 8 | 9586980 |
| 9 | 76695844 |
| 10 | 613566756 |
| 11 | 4908534052 |
| 12 | 39268272420 |
| 13 | 314146179364 |
| 14 | 2513169434916 |
| 15 | 20105355479332 |
| 16 | 160842843834660 |
| 17 | 1286742750677284 |
| 18 | 10293942005418276 |
| 19 | 82351536043346212 |