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 | 4 |
| 2 | 8 |
| 3 | 24 |
| 4 | 64 |
| 5 | 200 |
| 6 | 504 |
| 7 | 1400 |
| 8 | 3648 |
| 9 | 9720 |
| 10 | 25560 |
| 11 | 67936 |
| 12 | 178464 |
| 13 | 472576 |
| 14 | 1244208 |
| 15 | 3286080 |
| 16 | 8663232 |
| 17 | 22861600 |
| 18 | 60291504 |
| 19 | 159063744 |
| 20 | 419556560 |
| 21 | 1106794584 |
| 22 | 2919596768 |
| 23 | 7701735288 |
| 24 | 20316965760 |
| 25 | 53595401400 |
| 26 | 141384847344 |
| 27 | 372973574160 |
| 28 | 983911970608 |
| 29 | 2595592842456 |
| 30 | 6847273559040 |