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 | 1 |
| 3 | 25 |
| 4 | 25 |
| 5 | 745 |
| 6 | 3145 |
| 7 | 40945 |
| 8 | 353425 |
| 9 | 4200625 |
| 10 | 49949425 |
| 11 | 666656425 |
| 12 | 9492440425 |
| 13 | 145513569625 |
| 14 | 2378864325625 |
| 15 | 41355134658625 |
| 16 | 761412592638625 |
| 17 | 14800232282598625 |
| 18 | 302834714220150625 |