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 | 3 |
| 2 | 39 |
| 3 | 156 |
| 4 | 624 |
| 5 | 2496 |
| 6 | 9984 |
| 7 | 39936 |
| 8 | 159744 |
| 9 | 638976 |
| 10 | 2555904 |
| 11 | 10223616 |
| 12 | 40894464 |
| 13 | 163577856 |
| 14 | 654311424 |
| 15 | 2617245696 |
| 16 | 10468982784 |
| 17 | 41875931136 |
| 18 | 167503724544 |
| 19 | 670014898176 |
| 20 | 2680059592704 |
| 21 | 10720238370816 |
| 22 | 42880953483264 |
| 23 | 171523813933056 |
| 24 | 686095255732224 |