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 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 32 |
| 5 | 178 |
| 6 | 1164 |
| 7 | 8748 |
| 8 | 74304 |
| 9 | 704016 |
| 10 | 7362720 |
| 11 | 84255840 |
| 12 | 1047358080 |
| 13 | 14054739840 |
| 14 | 202514376960 |
| 15 | 3118666924800 |
| 16 | 51119166873600 |
| 17 | 888640952371200 |
| 18 | 16330301780889600 |
| 19 | 316322420114534400 |
| 20 | 6441691128993792000 |
| 21 | 137586770616637440000 |
| 22 | 3075566993729556480000 |