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 | 2 |
| 3 | 4 |
| 4 | 8 |
| 5 | 24 |
| 6 | 56 |
| 7 | 248 |
| 8 | 1016 |
| 9 | 5624 |
| 10 | 24056 |
| 11 | 208376 |
| 12 | 945656 |
| 13 | 9793016 |
| 14 | 62877176 |
| 15 | 487550456 |
| 16 | 3884936696 |
| 17 | 58243116536 |
| 18 | 384392195576 |
| 19 | 6255075618296 |
| 20 | 53220543000056 |
| 21 | 616806151581176 |
| 22 | 6252662237392376 |
| 23 | 130241496125238776 |
| 24 | 1122152167228009976 |
| 25 | 20960365589283433976 |