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 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 6 |
| 5 | 16 |
| 6 | 52 |
| 7 | 160 |
| 8 | 536 |
| 9 | 1796 |
| 10 | 6216 |
| 11 | 21752 |
| 12 | 77504 |
| 13 | 278720 |
| 14 | 1013184 |
| 15 | 3712128 |
| 16 | 13701204 |
| 17 | 50880808 |
| 18 | 190003808 |
| 19 | 712975648 |
| 20 | 2687114976 |
| 21 | 10167088608 |
| 22 | 38605365712 |
| 23 | 147060726688 |
| 24 | 561853414896 |
| 25 | 2152382687488 |
| 26 | 8265949250848 |
| 27 | 31817041756880 |
| 28 | 122728993889056 |