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 | 6 |
| 2 | 72 |
| 3 | 864 |
| 4 | 10368 |
| 5 | 124416 |
| 6 | 1492992 |
| 7 | 17915904 |
| 8 | 214990848 |
| 9 | 2579890176 |
| 10 | 30958682112 |
| 11 | 371504185344 |
| 12 | 4458050224128 |
| 13 | 53496602689536 |
| 14 | 641959232274432 |
| 15 | 7703510787293184 |
| 16 | 92442129447518208 |
| 17 | 1109305553370218496 |
| 18 | 13311666640442621952 |
| 19 | 159739999685311463424 |