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) |
|---|---|
| 6 | 1 |
| 7 | 21 |
| 8 | 322 |
| 9 | 4536 |
| 10 | 63273 |
| 11 | 902055 |
| 12 | 13339535 |
| 13 | 206070150 |
| 14 | 3336118786 |
| 15 | 56663366760 |
| 16 | 1009672107080 |
| 17 | 18861567058880 |
| 18 | 369012649234384 |
| 19 | 7551527592063024 |
| 20 | 161429736530118960 |
| 21 | 3599979517947607200 |
| 22 | 83637381699544802976 |
| 23 | 2021687376910682741568 |
| 24 | 50779532534302850198976 |
| 25 | 1323714091579185857760000 |