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 | 19 |
| 3 | 181 |
| 4 | 1639 |
| 5 | 14761 |
| 6 | 132859 |
| 7 | 1195741 |
| 8 | 10761679 |
| 9 | 96855121 |
| 10 | 871696099 |
| 11 | 7845264901 |
| 12 | 70607384119 |
| 13 | 635466457081 |
| 14 | 5719198113739 |
| 15 | 51472783023661 |
| 16 | 463255047212959 |
| 17 | 4169295424916641 |
| 18 | 37523658824249779 |
| 19 | 337712929418248021 |
| 20 | 3039416364764232199 |
| 21 | 27354747282878089801 |