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 | 4 |
| 4 | 14 |
| 5 | 54 |
| 6 | 233 |
| 7 | 1101 |
| 8 | 5625 |
| 9 | 30846 |
| 10 | 180474 |
| 11 | 1120666 |
| 12 | 7352471 |
| 13 | 50772653 |
| 14 | 367819093 |
| 15 | 2787354668 |
| 16 | 22039186530 |
| 17 | 181408823710 |
| 18 | 1551307538185 |
| 19 | 13756835638385 |
| 20 | 126298933271289 |
| 21 | 1198630386463990 |
| 22 | 11742905240821910 |