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) |
|---|---|
| 9 | 1 |
| 10 | 20 |
| 11 | 231 |
| 12 | 2024 |
| 13 | 14950 |
| 14 | 98280 |
| 15 | 593775 |
| 16 | 3365856 |
| 17 | 18156204 |
| 18 | 94143280 |
| 19 | 472733756 |
| 20 | 2311801440 |
| 21 | 11058116888 |
| 22 | 51915526432 |
| 23 | 239877544005 |
| 24 | 1093260079344 |
| 25 | 4923689695575 |
| 26 | 21945588357420 |
| 27 | 96926348578605 |
| 28 | 424655979547800 |
| 29 | 1847253511032930 |
| 30 | 7984465725343800 |
| 31 | 34315056105966195 |