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) |
---|---|
2 | -1 |
3 | -1 |
4 | -1 |
5 | -1 |
6 | -1 |
7 | 104 |
8 | 440 |
9 | 1440 |
10 | 4830 |
11 | 15552 |
12 | 72240 |
13 | 282240 |
14 | 1039104 |
15 | 4244940 |
16 | 24108000 |