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 | 0 |
| 2 | 2 |
| 3 | 4 |
| 4 | 9 |
| 5 | 20 |
| 6 | 44 |
| 7 | 96 |
| 8 | 208 |
| 9 | 448 |
| 10 | 960 |
| 11 | 2048 |
| 12 | 4352 |
| 13 | 9216 |
| 14 | 19456 |
| 15 | 40960 |
| 16 | 86016 |
| 17 | 180224 |
| 18 | 376832 |
| 19 | 786432 |
| 20 | 1638400 |
| 21 | 3407872 |
| 22 | 7077888 |
| 23 | 14680064 |
| 24 | 30408704 |
| 25 | 62914560 |
| 26 | 130023424 |
| 27 | 268435456 |
| 28 | 553648128 |
| 29 | 1140850688 |
| 30 | 2348810240 |