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 | 121 |
| 5 | 363 |
| 6 | 1331 |
| 7 | 4213 |
| 8 | 14641 |
| 9 | 46343 |
| 10 | 163251 |
| 11 | 531773 |
| 12 | 2015761 |
| 13 | 6051723 |
| 14 | 22175571 |
| 15 | 66571153 |
| 16 | 244153501 |
| 17 | 754502703 |
| 18 | 2705710511 |
| 19 | 10521531733 |
| 20 | 31765015621 |
| 21 | 115737051263 |
| 22 | 351635174031 |