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) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 11 |
| 3 | 33 |
| 4 | 103 |
| 5 | 309 |
| 6 | 935 |
| 7 | 2805 |
| 8 | 8431 |
| 9 | 25293 |
| 10 | 75911 |
| 11 | 227733 |
| 12 | 683263 |
| 13 | 2049789 |
| 14 | 6149495 |
| 15 | 18448485 |
| 16 | 55345711 |
| 17 | 166037133 |
| 18 | 498111911 |
| 19 | 1494335733 |
| 20 | 4483008223 |
| 21 | 13449024669 |
| 22 | 40347076055 |
| 23 | 121041228165 |
| 24 | 363123688591 |
| 25 | 1089371065773 |
| 26 | 3268113205511 |
| 27 | 9804339616533 |