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 | 1 |
| 2 | 12 |
| 3 | 210 |
| 4 | 5040 |
| 5 | 154440 |
| 6 | 5765760 |
| 7 | 253955520 |
| 8 | 12893126400 |
| 9 | 741354768000 |
| 10 | 47621141568000 |
| 11 | 3379847863392000 |
| 12 | 262662462526464000 |
| 13 | 22183557976419840000 |
| 14 | 2023140487449489408000 |
| 15 | 198155371076302768128000 |
| 16 | 20744817468539834621952000 |
| 17 | 2311708772421640603275264000 |