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 | 73 |
| 5 | 121 |
| 6 | 9721 |
| 7 | 5041 |
| 8 | 1760641 |
| 9 | 44452801 |
| 10 | 562615201 |
| 11 | 39916801 |
| 12 | 3156125575681 |
| 13 | 6227020801 |
| 14 | 192873372531841 |
| 15 | 222245415808416001 |
| 16 | 14806216643368550401 |
| 17 | 355687428096001 |
| 18 | 34884164976924636172801 |
| 19 | 121645100408832001 |