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 | 4 |
| 3 | 15 |
| 4 | 112 |
| 5 | 745 |
| 6 | 10296 |
| 7 | 122689 |
| 8 | 2285312 |
| 9 | 43953921 |
| 10 | 1026157600 |
| 11 | 25977341401 |
| 12 | 751135431168 |
| 13 | 23304312143281 |
| 14 | 795924137531264 |
| 15 | 29203006015310625 |
| 16 | 1154107395053387776 |
| 17 | 48661547563094964481 |
| 18 | 2186762596692631699968 |
| 19 | 104127471943011650364841 |