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 | 16 |
| 3 | 128 |
| 4 | 512 |
| 5 | 6144 |
| 6 | 98304 |
| 7 | 393216 |
| 8 | 9437184 |
| 9 | 37748736 |
| 10 | 1207959552 |
| 11 | 43486543872 |
| 12 | 1739461754880 |
| 13 | 6957847019520 |
| 14 | 333976656936960 |
| 15 | 1335906627747840 |
| 16 | 80154397664870400 |
| 17 | 4809263859892224000 |
| 18 | 19237055439568896000 |
| 19 | 1385067991648960512000 |
| 20 | 99724895398725156864000 |