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 | 4097 |
| 3 | 531442 |
| 4 | 16781313 |
| 5 | 244140626 |
| 6 | 1088658937 |
| 7 | 13841287202 |
| 8 | 68736258049 |
| 9 | 282430067923 |
| 10 | 500122072361 |
| 11 | 3138428376722 |
| 12 | 1486382423891 |
| 13 | 23298085122482 |
| 14 | 28353876833297 |
| 15 | 129746582562692 |
| 16 | 281543712968705 |
| 17 | 582622237229762 |
| 18 | 1157115988280531 |
| 19 | 2213314919066162 |
| 20 | 2048500130460969 |