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 | 3 |
| 3 | 14 |
| 4 | 50 |
| 5 | 324 |
| 6 | 1764 |
| 7 | 14832 |
| 8 | 109584 |
| 9 | 1136160 |
| 10 | 10628640 |
| 11 | 131172480 |
| 12 | 1486442880 |
| 13 | 21289201920 |
| 14 | 283465647360 |
| 15 | 4622628648960 |
| 16 | 70734282393600 |
| 17 | 1294139872972800 |
| 18 | 22376988058521600 |
| 19 | 453942134876160000 |
| 20 | 8752948036761600000 |