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 | 1 |
| 3 | 1 |
| 4 | 9 |
| 5 | 41 |
| 6 | 121 |
| 7 | 1401 |
| 8 | 11761 |
| 9 | 61489 |
| 10 | 864081 |
| 11 | 10597841 |
| 12 | 81833401 |
| 13 | 1350154521 |
| 14 | 21715461769 |
| 15 | 225232218121 |
| 16 | 4267472824161 |
| 17 | 84597818284001 |
| 18 | 1111699778741281 |
| 19 | 23801969674626849 |
| 20 | 558853937533757161 |
| 21 | 8943028907965939081 |
| 22 | 213696639293901810201 |