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 | 8 |
| 1 | 64 |
| 2 | 456 |
| 3 | 3200 |
| 4 | 22408 |
| 5 | 156864 |
| 6 | 1098056 |
| 7 | 7686400 |
| 8 | 53804808 |
| 9 | 376633664 |
| 10 | 2636435656 |
| 11 | 18455049600 |
| 12 | 129185347208 |
| 13 | 904297430464 |
| 14 | 6330082013256 |
| 15 | 44310574092800 |
| 16 | 310174018649608 |
| 17 | 2171218130547264 |
| 18 | 15198526913830856 |