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 | 1 |
| 3 | 10 |
| 4 | 123 |
| 5 | 2202 |
| 6 | 59040 |
| 7 | 2287680 |
| 8 | 121394000 |
| 9 | 92649740400 |
| 10 | 105538103163360 |
| 11 | 1034297134668000 |
| 12 | 134399089883282400 |
| 13 | 27076064087538702720 |
| 14 | 5451799851068349018240 |
| 15 | 19300076847195336557164800 |
| 16 | 4599598343095846092562560000 |
| 17 | 1682634821690958905899793664000 |