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 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 20 |
| 7 | 1 |
| 8 | 1 |
| 9 | 15876 |
| 10 | 1016255020032 |
| 11 | 1 |
| 12 | 728933458176 |
| 13 | 8670998958336 |
| 14 | 19247673071478783248355557376 |
| 15 | 1714723915100625 |
| 16 | 752711194884611945703392100000000 |
| 17 | 1 |
| 18 | 31226235883841773375939805209600000000 |
| 19 | 1 |
| 20 | 1357651828905889565182743230460164655087616 |