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 | 0 |
| 1 | 0 |
| 2 | 32 |
| 3 | 384 |
| 4 | 3072 |
| 5 | 20480 |
| 6 | 122880 |
| 7 | 688128 |
| 8 | 3670016 |
| 9 | 18874368 |
| 10 | 94371840 |
| 11 | 461373440 |
| 12 | 2214592512 |
| 13 | 10468982784 |
| 14 | 48855252992 |
| 15 | 225485783040 |
| 16 | 1030792151040 |
| 17 | 4672924418048 |
| 18 | 21028159881216 |
| 19 | 94008244174848 |
| 20 | 417814418554880 |