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 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 16 |
| 6 | 176 |
| 7 | 1536 |
| 8 | 15424 |
| 9 | 147728 |
| 10 | 1448416 |
| 11 | 14060048 |
| 12 | 136947616 |
| 13 | 1332257856 |
| 14 | 12965578752 |
| 15 | 126169362176 |
| 16 | 1227776129152 |
| 17 | 11947846468608 |
| 18 | 116266505653888 |
| 19 | 1131418872918784 |
| 20 | 11010065269439104 |
| 21 | 107141489725900544 |
| 22 | 1042616896632882688 |
| 23 | 10145938076107491328 |