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 | 7 |
| 3 | 15 |
| 4 | 32 |
| 5 | 70 |
| 6 | 156 |
| 7 | 348 |
| 8 | 768 |
| 9 | 1672 |
| 10 | 3600 |
| 11 | 7696 |
| 12 | 16384 |
| 13 | 34784 |
| 14 | 73664 |
| 15 | 155584 |
| 16 | 327680 |
| 17 | 688256 |
| 18 | 1442048 |
| 19 | 3014912 |
| 20 | 6291456 |
| 21 | 13106688 |
| 22 | 27261952 |
| 23 | 56622080 |
| 24 | 117440512 |
| 25 | 243271680 |
| 26 | 503320576 |
| 27 | 1040191488 |
| 28 | 2147483648 |