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 | 12 |
| 2 | 112 |
| 3 | 1296 |
| 4 | 20416 |
| 5 | 229680 |
| 6 | 2306304 |
| 7 | 32916240 |
| 8 | 400515072 |
| 9 | 3863116800 |
| 10 | 47825825600 |
| 11 | 685853880624 |
| 12 | 8732596764672 |
| 13 | 97509650382144 |
| 14 | 990242755633152 |
| 15 | 11148606564480000 |
| 16 | 184883057981234176 |
| 17 | 2047145911595946000 |
| 18 | 20281543142263603200 |
| 19 | 294779525244632305920 |