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 | 1 |
| 2 | 2 |
| 3 | 9 |
| 4 | 62 |
| 5 | 593 |
| 6 | 7266 |
| 7 | 108720 |
| 8 | 1922166 |
| 9 | 39212154 |
| 10 | 906623004 |
| 11 | 23429034168 |
| 12 | 669203550906 |
| 13 | 20935080981744 |
| 14 | 711872134399868 |
| 15 | 26142553369667634 |
| 16 | 1031146768716808794 |
| 17 | 43475757877044427198 |
| 18 | 1951261759908828697902 |