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 | 4 |
| 1 | 9 |
| 2 | 284 |
| 3 | 61209 |
| 4 | 14204828164 |
| 5 | 4440027571600000000001 |
| 6 | 7667716927194638935286982918857620344809476 |