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 | 1 |
| 2 | 6 |
| 3 | 52 |
| 4 | 588 |
| 5 | 8174 |
| 6 | 134537 |
| 7 | 2554647 |
| 8 | 54909468 |
| 9 | 1316675221 |
| 10 | 34820961457 |
| 11 | 1006230148609 |
| 12 | 31529224324159 |
| 13 | 1064355502971193 |
| 14 | 38497326001639439 |
| 15 | 1484865225798412485 |
| 16 | 60822449267067095601 |
| 17 | 2636248249383130776940 |
| 18 | 120520100503562054999860 |
| 19 | 5794815395039941996204424 |