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 | 2 |
| 2 | 6 |
| 3 | 26 |
| 4 | 182 |
| 5 | 2170 |
| 6 | 45640 |
| 7 | 1728722 |
| 8 | 119663816 |
| 9 | 15307529470 |
| 10 | 3650708270236 |
| 11 | 1634796996516742 |
| 12 | 1382620288569817496 |