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 | 1 |
| 2 | 7 |
| 3 | 25 |
| 4 | 71 |
| 5 | 181 |
| 6 | 435 |
| 7 | 1009 |
| 8 | 2287 |
| 9 | 5101 |
| 10 | 11243 |
| 11 | 24553 |
| 12 | 53223 |
| 13 | 114661 |
| 14 | 245731 |
| 15 | 524257 |
| 16 | 1114079 |
| 17 | 2359261 |
| 18 | 4980699 |
| 19 | 10485721 |
| 20 | 22020055 |
| 21 | 46137301 |
| 22 | 96468947 |
| 23 | 201326545 |
| 24 | 419430351 |
| 25 | 872415181 |
| 26 | 1811939275 |
| 27 | 3758096329 |
| 28 | 7784628167 |