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 | 27 |
| 4 | 513 |
| 5 | 540702 |
| 6 | 8891844390 |
| 7 | 27306854121690 |
| 8 | 94235953573952190 |
| 9 | 1684561906087969348440 |
| 10 | 1106757172299795861925080 |
| 11 | 8644064410182787098480243878401800 |
| 12 | 289900692457541891469406183557646377576408600 |
| 13 | 1206267931807293851480420134690207296382114287151076400 |