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 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 27 |
| 5 | 83 |
| 6 | 259 |
| 7 | 817 |
| 8 | 2599 |
| 9 | 8323 |
| 10 | 26797 |
| 11 | 86659 |
| 12 | 281287 |
| 13 | 915907 |
| 14 | 2990383 |
| 15 | 9786369 |
| 16 | 32092959 |
| 17 | 105435607 |
| 18 | 346950321 |
| 19 | 1143342603 |
| 20 | 3772698725 |
| 21 | 12463525229 |
| 22 | 41218894577 |
| 23 | 136451431723 |
| 24 | 452116980643 |
| 25 | 1499282161375 |
| 26 | 4975631425581 |
| 27 | 16524213199923 |
| 28 | 54913514061867 |