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 | 0 |
| 2 | 2 |
| 3 | 4 |
| 4 | 12 |
| 5 | 24 |
| 6 | 60 |
| 7 | 120 |
| 8 | 264 |
| 9 | 528 |
| 10 | 1116 |
| 11 | 2232 |
| 12 | 4584 |
| 13 | 9168 |
| 14 | 18616 |
| 15 | 37232 |
| 16 | 75056 |
| 17 | 150112 |
| 18 | 301556 |
| 19 | 603112 |
| 20 | 1209064 |
| 21 | 2418128 |
| 22 | 4842504 |
| 23 | 9685008 |
| 24 | 19383408 |
| 25 | 38766816 |
| 26 | 77562648 |
| 27 | 155125296 |
| 28 | 310312528 |
| 29 | 620625056 |
| 30 | 1241382832 |
| 31 | 2482765664 |
| 32 | 4965813280 |
| 33 | 9931626560 |