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 | 7 |
| 4 | 49 |
| 5 | 121 |
| 6 | 2521 |
| 7 | 5041 |
| 8 | 208321 |
| 9 | 907201 |
| 10 | 32810401 |
| 11 | 39916801 |
| 12 | 10621860481 |
| 13 | 6227020801 |
| 14 | 2877004690561 |
| 15 | 19233710496001 |
| 16 | 1415779600435201 |
| 17 | 355687428096001 |
| 18 | 1085522620595212801 |
| 19 | 121645100408832001 |
| 20 | 653741050484890368001 |
| 21 | 6259137133527742464001 |
| 22 | 576612373659657208473601 |