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 | 10 |
| 3 | 75 |
| 4 | 628 |
| 5 | 6325 |
| 6 | 75966 |
| 7 | 1063615 |
| 8 | 17017960 |
| 9 | 306323433 |
| 10 | 6126468850 |
| 11 | 134782314931 |
| 12 | 3234775558620 |
| 13 | 84104164524445 |
| 14 | 2354916606684838 |
| 15 | 70647498200545575 |
| 16 | 2260719942417458896 |
| 17 | 76864478042193603025 |
| 18 | 2767121209518969709530 |
| 19 | 105150605961720848962843 |
| 20 | 4206024238468833958514500 |