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 | 3 |
| 1 | 6 |
| 2 | 66 |
| 3 | 137346 |
| 4 | 1295413937737986 |
| 5 | 1086915296274625337063297033180803022465442306 |