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) |
|---|---|
| 2 | 1 |
| 3 | 12 |
| 4 | 108 |
| 5 | 960 |
| 6 | 9000 |
| 7 | 90720 |
| 8 | 987840 |
| 9 | 11612160 |
| 10 | 146966400 |
| 11 | 1995840000 |
| 12 | 28979596800 |
| 13 | 448345497600 |
| 14 | 7366565606400 |
| 15 | 128152088064000 |
| 16 | 2353813862400000 |
| 17 | 45527990796288000 |
| 18 | 925143000477696000 |