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 | 5 |
| 4 | 17 |
| 5 | 129 |
| 6 | 769 |
| 7 | 7797 |
| 8 | 66849 |
| 9 | 848481 |
| 10 | 9506241 |
| 11 | 145041093 |
| 12 | 2007271089 |
| 13 | 35799178401 |
| 14 | 589807203777 |
| 15 | 12045448529397 |
| 16 | 230194642564161 |
| 17 | 5298881528389185 |
| 18 | 115219444193968257 |
| 19 | 2952169020073027845 |