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 | 9 |
| 1 | 25 |
| 2 | 73 |
| 3 | 217 |
| 4 | 649 |
| 5 | 1945 |
| 6 | 5833 |
| 7 | 17497 |
| 8 | 52489 |
| 9 | 157465 |
| 10 | 472393 |
| 11 | 1417177 |
| 12 | 4251529 |
| 13 | 12754585 |
| 14 | 38263753 |
| 15 | 114791257 |
| 16 | 344373769 |
| 17 | 1033121305 |
| 18 | 3099363913 |
| 19 | 9298091737 |
| 20 | 27894275209 |
| 21 | 83682825625 |
| 22 | 251048476873 |
| 23 | 753145430617 |
| 24 | 2259436291849 |
| 25 | 6778308875545 |
| 26 | 20334926626633 |
| 27 | 61004779879897 |