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 | 60 |
| 3 | 15652352 |
| 4 | 18446731528483929840 |
| 5 | 1461501637330902918203677267647731623106580665344 |
| 6 | 3940200619639447921227904010014361380507973 |