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 | 6 |
| 3 | 120 |
| 4 | 4845 |
| 5 | 324632 |
| 6 | 32468436 |
| 7 | 4529365776 |
| 8 | 840261910995 |
| 9 | 200063149171380 |
| 10 | 59473554359599446 |
| 11 | 21592914273609648996 |
| 12 | 9403538945961296957821 |
| 13 | 4838670732821812768919800 |
| 14 | 2904538537066424425438417800 |