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) |
|---|---|
| 3 | 1 |
| 4 | 18 |
| 5 | 9 |
| 6 | 432 |
| 7 | 1 |
| 8 | 672 |
| 9 | 14400 |
| 10 | 243 |
| 11 | 47520 |
| 12 | 648000 |
| 13 | 27 |
| 14 | 36396 |
| 15 | 3790800 |
| 16 | 38102400 |
| 17 | 1 |
| 18 | 9765 |
| 19 | 5115888 |
| 20 | 354715200 |
| 21 | 2844979200 |
| 22 | 1107 |
| 23 | 2499552 |
| 24 | 757646784 |
| 25 | 39182330880 |
| 26 | 263363788800 |
| 27 | 54 |
| 28 | 546453 |
| 29 | 592216272 |
| 30 | 123294623040 |
| 31 | 5089348454400 |