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 | 0 |
| 2 | 72 |
| 3 | 384 |
| 4 | 8544 |
| 5 | 76800 |
| 6 | 1168512 |
| 7 | 12785664 |
| 8 | 170678784 |
| 9 | 2014648320 |
| 10 | 25633231872 |
| 11 | 311423852544 |
| 12 | 3892030055424 |
| 13 | 47803588208640 |
| 14 | 593425578949632 |
| 15 | 7318730222874624 |
| 16 | 90624271197041664 |
| 17 | 1119402280975349760 |
| 18 | 13847850677651745792 |
| 19 | 171150049715628539904 |