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 | 2 |
| 1 | 4 |
| 2 | 8 |
| 3 | 20 |
| 4 | 100 |
| 5 | 2116 |
| 6 | 1114244 |
| 7 | 68723671300 |
| 8 | 1180735735906024030724 |
| 9 | 170141183460507917357914971986913657860 |