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 | 4 |
| 2 | 6 |
| 3 | 12 |
| 4 | 25 |
| 5 | 56 |
| 6 | 132 |
| 7 | 320 |
| 8 | 792 |
| 9 | 1976 |
| 10 | 4962 |
| 11 | 12576 |
| 12 | 32140 |
| 13 | 82704 |
| 14 | 214044 |
| 15 | 556576 |
| 16 | 1453210 |
| 17 | 3808592 |
| 18 | 10015134 |
| 19 | 26413468 |
| 20 | 69844263 |
| 21 | 185126524 |
| 22 | 491758054 |
| 23 | 1308874676 |
| 24 | 3490068514 |
| 25 | 9321677540 |
| 26 | 24935748182 |
| 27 | 66798957432 |