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 | 2 |
| 1 | 3 |
| 2 | 18 |
| 3 | 128 |
| 4 | 2100 |
| 5 | 61600 |
| 6 | 3732480 |
| 7 | 449880480 |
| 8 | 111021510600 |
| 9 | 55916730777600 |
| 10 | 57813913372723200 |
| 11 | 122742264040428032000 |
| 12 | 535797463154791219200000 |
| 13 | 4810427190599491339840000000 |
| 14 | 88856328051357049141036014736800 |
| 15 | 3377300175611111321142254817509376000 |