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 | 18 |
| 4 | 48 |
| 5 | 300 |
| 6 | 120 |
| 7 | 980 |
| 8 | 2240 |
| 9 | 22680 |
| 10 | 25200 |
| 11 | 304920 |
| 12 | 332640 |
| 13 | 4684680 |
| 14 | 5045040 |
| 15 | 5405400 |
| 16 | 11531520 |
| 17 | 208288080 |
| 18 | 73513440 |
| 19 | 1474352880 |
| 20 | 62078016 |
| 21 | 108636528 |
| 22 | 113809696 |
| 23 | 2736605872 |
| 24 | 8566766208 |
| 25 | 223092870000 |
| 26 | 232016584800 |