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 | 90 |
| 2 | 6156 |
| 3 | 387720 |
| 4 | 23705136 |
| 5 | 1432922400 |
| 6 | 86230132416 |
| 7 | 5179923146880 |
| 8 | 310942155338496 |
| 9 | 18660051727004160 |
| 10 | 1119687641441381376 |
| 11 | 67183287394552842240 |
| 12 | 4031045937469026349056 |
| 13 | 241863924899255181189120 |