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) |
|---|---|
| 2 | 1 |
| 3 | 6 |
| 4 | 23 |
| 5 | 76 |
| 6 | 237 |
| 7 | 722 |
| 8 | 2179 |
| 9 | 6552 |
| 10 | 19673 |
| 11 | 59038 |
| 12 | 177135 |
| 13 | 531428 |
| 14 | 1594309 |
| 15 | 4782954 |
| 16 | 14348891 |
| 17 | 43046704 |
| 18 | 129140145 |
| 19 | 387420470 |
| 20 | 1162261447 |
| 21 | 3486784380 |
| 22 | 10460353181 |
| 23 | 31381059586 |
| 24 | 94143178803 |
| 25 | 282429536456 |
| 26 | 847288609417 |