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 | 28 |
| 4 | 119 |
| 5 | 451 |
| 6 | 1782 |
| 7 | 6931 |
| 8 | 27119 |
| 9 | 105868 |
| 10 | 413649 |
| 11 | 1615681 |
| 12 | 6311522 |
| 13 | 24654241 |
| 14 | 96306849 |
| 15 | 376200748 |
| 16 | 1469546399 |
| 17 | 5740457491 |
| 18 | 22423834422 |
| 19 | 87593763331 |
| 20 | 342165736199 |
| 21 | 1336595027068 |
| 22 | 5221113899769 |
| 23 | 20395130698081 |
| 24 | 79669083012482 |