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 | 8 |
| 3 | 72 |
| 4 | 2160 |
| 5 | 15504 |
| 6 | 220248 |
| 7 | 1564920 |
| 8 | 89324640 |
| 9 | 640807200 |
| 10 | 9246847896 |
| 11 | 67087213336 |
| 12 | 1957095947664 |
| 13 | 14342471475696 |
| 14 | 211153052281080 |
| 15 | 1560676296310488 |
| 16 | 185256494416099008 |
| 17 | 1379131680653181504 |
| 18 | 20598677144877854232 |