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 | 6 |
| 2 | 25 |
| 3 | 93 |
| 4 | 333 |
| 5 | 1180 |
| 6 | 4183 |
| 7 | 14895 |
| 8 | 53349 |
| 9 | 192239 |
| 10 | 696765 |
| 11 | 2539157 |
| 12 | 9299547 |
| 13 | 34215102 |
| 14 | 126411177 |
| 15 | 468822297 |
| 16 | 1744799967 |
| 17 | 6514363557 |
| 18 | 24393558687 |
| 19 | 91591471287 |
| 20 | 344764147407 |
| 21 | 1300756937445 |
| 22 | 4918188617379 |
| 23 | 18633066901747 |