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 | 18 |
| 2 | 255 |
| 3 | 3465 |
| 4 | 47880 |
| 5 | 687960 |
| 6 | 10372320 |
| 7 | 164656800 |
| 8 | 2754259200 |
| 9 | 48518870400 |
| 10 | 899026128000 |
| 11 | 17495593315200 |
| 12 | 356995102464000 |
| 13 | 7625049239808000 |
| 14 | 170196434343936000 |
| 15 | 3963602854987776000 |
| 16 | 96160451873181696000 |