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) |
|---|---|
| 4 | 2 |
| 5 | 14 |
| 6 | 89 |
| 7 | 629 |
| 8 | 5039 |
| 9 | 45359 |
| 10 | 453599 |
| 11 | 4989599 |
| 12 | 59875199 |
| 13 | 778377599 |
| 14 | 10897286399 |
| 15 | 163459295999 |
| 16 | 2615348735999 |
| 17 | 44460928511999 |
| 18 | 800296713215999 |
| 19 | 15205637551103999 |
| 20 | 304112751022079999 |