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 | 16 |
| 3 | 80 |
| 4 | 336 |
| 5 | 1360 |
| 6 | 5456 |
| 7 | 21840 |
| 8 | 87376 |
| 9 | 349520 |
| 10 | 1398096 |
| 11 | 5592400 |
| 12 | 22369616 |
| 13 | 89478480 |
| 14 | 357913936 |
| 15 | 1431655760 |
| 16 | 5726623056 |
| 17 | 22906492240 |
| 18 | 91625968976 |
| 19 | 366503875920 |
| 20 | 1466015503696 |
| 21 | 5864062014800 |
| 22 | 23456248059216 |
| 23 | 93824992236880 |
| 24 | 375299968947536 |
| 25 | 1501199875790160 |