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 | 1 |
| 3 | 3 |
| 4 | 9 |
| 5 | 135 |
| 6 | 2025 |
| 7 | 212625 |
| 8 | 22325625 |
| 9 | 21097715625 |
| 10 | 19937341265625 |
| 11 | 207248662456171875 |
| 12 | 2154349846231906640625 |
| 13 | 291128066470548703880859375 |
| 14 | 39341591262497599098939931640625 |
| 15 | 79746389028864195813528714933837890625 |