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 | 1 |
| 2 | 4 |
| 3 | 24 |
| 4 | 192 |
| 5 | 2304 |
| 6 | 32256 |
| 7 | 580608 |
| 8 | 11612160 |
| 9 | 278691840 |
| 10 | 8360755200 |
| 11 | 267544166400 |
| 12 | 10166678323200 |
| 13 | 427000489574400 |
| 14 | 18788021541273600 |
| 15 | 901825033981132800 |
| 16 | 48698551834981171200 |
| 17 | 2921913110098870272000 |
| 18 | 181158612826129956864000 |
| 19 | 12318785672176837066752000 |