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 | 13 |
| 2 | 121 |
| 3 | 763 |
| 4 | 7779 |
| 5 | 58901 |
| 6 | 514945 |
| 7 | 4279111 |
| 8 | 35870939 |
| 9 | 302197213 |
| 10 | 2529537475 |
| 11 | 21265881307 |
| 12 | 178394566329 |
| 13 | 1497728421519 |
| 14 | 12572164720815 |
| 15 | 105527179560835 |
| 16 | 885843035970095 |
| 17 | 7435701167074899 |
| 18 | 62416764116955877 |
| 19 | 523932061650568927 |