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 | 3 |
| 4 | 12 |
| 5 | 82 |
| 6 | 732 |
| 7 | 8801 |
| 8 | 125970 |
| 9 | 2230928 |
| 10 | 50152660 |
| 11 | 1253503063 |
| 12 | 37668721496 |
| 13 | 1278362451795 |
| 14 | 46557869507722 |
| 15 | 1874663971306376 |
| 16 | 85535849021496180 |
| 17 | 4369909886714119634 |
| 18 | 234108545627558824317 |
| 19 | 13835073153310329323730 |