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 | 0 |
| 2 | 24 |
| 3 | 96 |
| 4 | 168 |
| 5 | 1200 |
| 6 | 3960 |
| 7 | 16128 |
| 8 | 66888 |
| 9 | 259152 |
| 10 | 1052184 |
| 11 | 4195488 |
| 12 | 16759272 |
| 13 | 67158000 |
| 14 | 268359864 |
| 15 | 1073772096 |
| 16 | 4295178888 |
| 17 | 17179113360 |
| 18 | 68720897880 |
| 19 | 274876666848 |
| 20 | 1099509663528 |
| 21 | 4398057364272 |
| 22 | 17592161341944 |
| 23 | 70368774872448 |
| 24 | 281474983436232 |
| 25 | 1125899763886800 |