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 | 6 |
| 3 | 6 |
| 4 | 6 |
| 5 | 6 |
| 6 | 42 |
| 7 | 42 |
| 8 | 210 |
| 9 | 210 |
| 10 | 210 |
| 11 | 210 |
| 12 | 3990 |
| 13 | 3990 |
| 14 | 43890 |
| 15 | 43890 |
| 16 | 43890 |
| 17 | 43890 |
| 18 | 1360590 |
| 19 | 23130030 |
| 20 | 23130030 |
| 21 | 855811110 |
| 22 | 855811110 |
| 23 | 855811110 |
| 24 | 855811110 |
| 25 | 855811110 |
| 26 | 855811110 |
| 27 | 11125544430 |
| 28 | 11125544430 |
| 29 | 11125544430 |
| 30 | 11125544430 |