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 | 3 |
| 3 | 9 |
| 4 | 25 |
| 5 | 71 |
| 6 | 195 |
| 7 | 543 |
| 8 | 1479 |
| 9 | 4067 |
| 10 | 11025 |
| 11 | 30073 |
| 12 | 81233 |
| 13 | 220375 |
| 14 | 593611 |
| 15 | 1604149 |
| 16 | 4311333 |
| 17 | 11616669 |
| 18 | 31164683 |
| 19 | 83779155 |
| 20 | 224424291 |
| 21 | 602201507 |
| 22 | 1611140121 |
| 23 | 4316653453 |
| 24 | 11536599329 |
| 25 | 30870338727 |
| 26 | 82428196555 |
| 27 | 220329372907 |