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 | 1 |
| 1 | 56 |
| 2 | 1792 |
| 3 | 43008 |
| 4 | 860160 |
| 5 | 15138816 |
| 6 | 242221056 |
| 7 | 3598712832 |
| 8 | 50381979648 |
| 9 | 671759728640 |
| 10 | 8598524526592 |
| 11 | 106309030510592 |
| 12 | 1275708366127104 |
| 13 | 14915974742409216 |
| 14 | 170468282770391040 |
| 15 | 1909244767028379648 |
| 16 | 21001692437312176128 |
| 17 | 227312435792084729856 |