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 | 6 |
| 2 | 42 |
| 3 | 558 |
| 4 | 8640 |
| 5 | 151350 |
| 6 | 2858562 |
| 7 | 57010422 |
| 8 | 1183184640 |
| 9 | 25319269980 |
| 10 | 555099603450 |
| 11 | 12411545042094 |
| 12 | 282060978777792 |
| 13 | 6498315236374338 |
| 14 | 151469476107975354 |
| 15 | 3566331985691591550 |
| 16 | 84709091524784348160 |