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 | 1280 |
| 6 | 7680 |
| 7 | 48384 |
| 8 | 315392 |
| 9 | 1916928 |
| 10 | 11182080 |
| 11 | 72089600 |
| 12 | 441188352 |
| 13 | 2589982720 |
| 14 | 15863644160 |
| 15 | 97493975040 |
| 16 | 578813952000 |
| 17 | 3411143557120 |
| 18 | 21023026053120 |
| 19 | 125795699785728 |
| 20 | 733623363829760 |
| 21 | 4459657816965120 |
| 22 | 26839963597275136 |
| 23 | 157885776644800512 |