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 | 11 |
| 3 | 37 |
| 4 | 71 |
| 5 | 252 |
| 6 | 539 |
| 7 | 1813 |
| 8 | 4271 |
| 9 | 13519 |
| 10 | 34276 |
| 11 | 103803 |
| 12 | 276119 |
| 13 | 813417 |
| 14 | 2226851 |
| 15 | 6455052 |
| 16 | 17965151 |
| 17 | 51604017 |
| 18 | 144948419 |
| 19 | 414258603 |
| 20 | 1169523076 |
| 21 | 3333192319 |
| 22 | 9436433171 |
| 23 | 26853404413 |
| 24 | 76139155439 |
| 25 | 216490730652 |
| 26 | 614339685971 |
| 27 | 1745997031837 |
| 28 | 4956888901511 |