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) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 9 |
| 3 | 27 |
| 4 | 75 |
| 5 | 189 |
| 6 | 447 |
| 7 | 951 |
| 8 | 1911 |
| 9 | 3621 |
| 10 | 6513 |
| 11 | 11103 |
| 12 | 18267 |
| 13 | 29013 |
| 14 | 44691 |
| 15 | 67251 |
| 16 | 98547 |
| 17 | 140865 |
| 18 | 197679 |
| 19 | 272799 |
| 20 | 370659 |
| 21 | 497403 |
| 22 | 658371 |
| 23 | 859863 |
| 24 | 1110453 |
| 25 | 1420527 |
| 26 | 1799373 |
| 27 | 2260161 |
| 28 | 2815401 |
| 29 | 3479235 |
| 30 | 4269279 |