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 | 4 |
| 1 | 8 |
| 2 | 24 |
| 3 | 80 |
| 4 | 272 |
| 5 | 928 |
| 6 | 3168 |
| 7 | 10816 |
| 8 | 36928 |
| 9 | 126080 |
| 10 | 430464 |
| 11 | 1469696 |
| 12 | 5017856 |
| 13 | 17132032 |
| 14 | 58492416 |
| 15 | 199705600 |
| 16 | 681837568 |
| 17 | 2327939072 |
| 18 | 7948081152 |
| 19 | 27136446464 |
| 20 | 92649623552 |
| 21 | 316325601280 |
| 22 | 1080003158016 |
| 23 | 3687361429504 |
| 24 | 12589439401984 |
| 25 | 42983034748928 |