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 | 10 |
| 3 | 325 |
| 4 | 22150 |
| 5 | 2586250 |
| 6 | 461242900 |
| 7 | 116651486125 |
| 8 | 39713286199150 |
| 9 | 17511670912894750 |
| 10 | 9709015945443877900 |
| 11 | 6610669330703494665250 |
| 12 | 5422712627276230973347900 |
| 13 | 5274585355686671613655544500 |