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 | 0 |
| 1 | 8 |
| 2 | 72 |
| 3 | 528 |
| 4 | 4176 |
| 5 | 32800 |
| 6 | 262800 |
| 7 | 2097200 |
| 8 | 16781472 |
| 9 | 134218800 |
| 10 | 1073774880 |
| 11 | 8589934672 |
| 12 | 68719748256 |
| 13 | 549755813984 |
| 14 | 4398048608688 |
| 15 | 35184372156480 |
| 16 | 281474993496384 |
| 17 | 2251799813685376 |
| 18 | 18014398644225456 |
| 19 | 144115188075856016 |