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) |
|---|---|
| 0 | 1 |
| 1 | 4 |
| 2 | 32 |
| 3 | 272 |
| 4 | 2400 |
| 5 | 21792 |
| 6 | 203008 |
| 7 | 1940224 |
| 8 | 19065344 |
| 9 | 193410560 |
| 10 | 2038078464 |
| 11 | 22490167296 |
| 12 | 262429339648 |
| 13 | 3271314362368 |
| 14 | 43955391856640 |
| 15 | 640254018879488 |
| 16 | 10121874150653952 |
| 17 | 173145693892509696 |
| 18 | 3186234896556752896 |