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 | 3 |
| 2 | 5 |
| 3 | 9 |
| 4 | 21 |
| 5 | 49 |
| 6 | 122 |
| 7 | 313 |
| 8 | 821 |
| 9 | 2187 |
| 10 | 5905 |
| 11 | 16105 |
| 12 | 44287 |
| 13 | 122641 |
| 14 | 341641 |
| 15 | 956594 |
| 16 | 2690421 |
| 17 | 7596481 |
| 18 | 21523361 |
| 19 | 61171657 |
| 20 | 174339221 |
| 21 | 498112058 |
| 22 | 1426411801 |
| 23 | 4093181689 |
| 24 | 11767897354 |
| 25 | 33891544378 |
| 26 | 97764070321 |
| 27 | 282429536481 |