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 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 11 |
| 5 | 38 |
| 6 | 946 |
| 7 | 4580 |
| 8 | 202738 |
| 9 | 3786092 |
| 10 | 261868876 |
| 11 | 1992367192 |
| 12 | 2381255244240 |
| 13 | 21411255538848 |
| 14 | 2902625722978656 |
| 15 | 451716954504285504 |
| 16 | 319933105641374465472 |
| 17 | 3761845343198709705600 |