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 | 15 |
| 3 | 1551 |
| 4 | 14164693 |
| 5 | 847881355388 |
| 6 | 5219870359015849505 |
| 7 | 70570762532647014868797563 |
| 8 | 62256944108221643391817947390337742 |
| 9 | 103256072887229091159525820942838733556042886 |