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 | 2 |
| 2 | 8 |
| 3 | 20 |
| 4 | 44 |
| 5 | 92 |
| 6 | 188 |
| 7 | 380 |
| 8 | 764 |
| 9 | 1532 |
| 10 | 3068 |
| 11 | 6140 |
| 12 | 12284 |
| 13 | 24572 |
| 14 | 49148 |
| 15 | 98300 |
| 16 | 196604 |
| 17 | 393212 |
| 18 | 786428 |
| 19 | 1572860 |
| 20 | 3145724 |
| 21 | 6291452 |
| 22 | 12582908 |
| 23 | 25165820 |
| 24 | 50331644 |
| 25 | 100663292 |
| 26 | 201326588 |
| 27 | 402653180 |
| 28 | 805306364 |
| 29 | 1610612732 |
| 30 | 3221225468 |