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 | 0 |
| 2 | 1 |
| 3 | 5 |
| 4 | 17 |
| 5 | 185 |
| 6 | 629 |
| 7 | 7709 |
| 8 | 27593 |
| 9 | 364721 |
| 10 | 18512789 |
| 11 | 69273665 |
| 12 | 3714566309 |
| 13 | 53634713549 |
| 14 | 204560302841 |
| 15 | 2994414645857 |
| 16 | 169947155749829 |
| 17 | 9770521225481753 |
| 18 | 37800705069076949 |
| 19 | 2202596307308603177 |