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 | 3 |
| 3 | 10 |
| 4 | 73 |
| 5 | 626 |
| 6 | 8052 |
| 7 | 117650 |
| 8 | 2113665 |
| 9 | 43053283 |
| 10 | 1001953638 |
| 11 | 25937424602 |
| 12 | 743375541244 |
| 13 | 23298085122482 |
| 14 | 793811662272744 |
| 15 | 29192932133689220 |
| 16 | 1152956690052710401 |
| 17 | 48661191875666868482 |
| 18 | 2185928253847184914509 |