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 | 3 |
| 2 | 5 |
| 3 | 28 |
| 4 | 72 |
| 5 | 704 |
| 6 | 1664 |
| 7 | 2560 |
| 8 | 17408 |
| 9 | 311296 |
| 10 | 688128 |
| 11 | 3014656 |
| 12 | 6553600 |
| 13 | 56623104 |
| 14 | 121634816 |
| 15 | 520093696 |
| 16 | 369098752 |
| 17 | 7516192768 |
| 18 | 79456894976 |
| 19 | 111669149696 |
| 20 | 704374636544 |
| 21 | 5909874999296 |
| 22 | 824633720832 |
| 23 | 51677046505472 |