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) |
|---|---|
| 0 | 18 |
| 1 | 750 |
| 2 | 20250 |
| 3 | 463050 |
| 4 | 9878400 |
| 5 | 205752960 |
| 6 | 4286520000 |
| 7 | 90561240000 |
| 8 | 1956122784000 |
| 9 | 43410118752000 |
| 10 | 992644715462400 |
| 11 | 23427803599200000 |
| 12 | 571192163942400000 |
| 13 | 14391113340764160000 |
| 14 | 374682915193466880000 |
| 15 | 10078235746321526784000 |
| 16 | 279950992953375744000000 |
| 17 | 8026706333564126208000000 |