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 | 1 |
| 2 | 9 |
| 3 | 216 |
| 4 | 9936 |
| 5 | 745200 |
| 6 | 82717200 |
| 7 | 12738448800 |
| 8 | 2598643555200 |
| 9 | 678245967907200 |
| 10 | 220429939569840000 |
| 11 | 87290256069656640000 |
| 12 | 41375581377017247360000 |
| 13 | 23128949989752641274240000 |
| 14 | 15056946443328969469530240000 |
| 15 | 11292709832496727102147680000000 |
| 16 | 9666559616617198399438414080000000 |