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) |
|---|---|
| 1 | 4 |
| 2 | 24 |
| 3 | 216 |
| 4 | 2160 |
| 5 | 30240 |
| 6 | 453600 |
| 7 | 9525600 |
| 8 | 209563200 |
| 9 | 5239080000 |
| 10 | 136216080000 |
| 11 | 4495130640000 |
| 12 | 152834441760000 |
| 13 | 5349205461600000 |
| 14 | 203269807540800000 |
| 15 | 7927522494091200000 |
| 16 | 364666034728195200000 |
| 17 | 17868635701681564800000 |
| 18 | 911300420785759804800000 |