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 | 7 |
| 3 | 109 |
| 4 | 3207 |
| 5 | 174581 |
| 6 | 17929279 |
| 7 | 3559607005 |
| 8 | 1389312382199 |
| 9 | 1075527698708485 |
| 10 | 1658535837898129263 |
| 11 | 5105026337441341642861 |
| 12 | 31395991691829167745766311 |
| 13 | 385982564381552315528268500501 |