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 | 30 |
| 2 | 15 |
| 3 | 105 |
| 4 | 210 |
| 5 | 2310 |
| 6 | 5005 |
| 7 | 1616615 |
| 8 | 9699690 |
| 9 | 223092870 |
| 10 | 111546435 |
| 11 | 2156564410 |
| 12 | 100280245065 |
| 13 | 3710369067405 |
| 14 | 7420738134810 |
| 15 | 6541380665835015 |