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 | 5 |
| 3 | 13490 |
| 4 | 3299391550 |
| 5 | 22042432252064127 |
| 6 | 2387505511919644051 |
| 7 | 680588297594638712735 |