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 | 7 |
| 2 | 62 |
| 3 | 664 |
| 4 | 8609 |
| 5 | 127415 |
| 6 | 2004975 |
| 7 | 31500927 |
| 8 | 474504448 |
| 9 | 6708348262 |
| 10 | 88249739792 |
| 11 | 1078567590128 |
| 12 | 12269901302433 |
| 13 | 130370516668917 |
| 14 | 1298891291366245 |
| 15 | 12182760243381355 |
| 16 | 107979270564656625 |
| 17 | 907568508195185203 |
| 18 | 7256984238345563764 |
| 19 | 55365443728411530716 |
| 20 | 404091280028746802188 |