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 | 9 |
| 3 | 53 |
| 4 | 341 |
| 5 | 2169 |
| 6 | 13825 |
| 7 | 88093 |
| 8 | 561357 |
| 9 | 3577121 |
| 10 | 22794425 |
| 11 | 145252485 |
| 12 | 925589701 |
| 13 | 5898117961 |
| 14 | 37584466929 |
| 15 | 239498796653 |
| 16 | 1526153708861 |
| 17 | 9725080775409 |
| 18 | 61970950592425 |
| 19 | 394896331045333 |
| 20 | 2516390514947637 |