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 | 1 |
| 3 | 1 |
| 4 | 6 |
| 5 | 1 |
| 6 | 30 |
| 7 | 1 |
| 8 | 140 |
| 9 | 1 |
| 10 | 630 |
| 11 | 1 |
| 12 | 2772 |
| 13 | 1 |
| 14 | 12012 |
| 15 | 1 |
| 16 | 51480 |
| 17 | 1 |
| 18 | 218790 |
| 19 | 1 |
| 20 | 923780 |
| 21 | 1 |
| 22 | 3879876 |
| 23 | 1 |
| 24 | 16224936 |
| 25 | 1 |
| 26 | 67603900 |
| 27 | 1 |
| 28 | 280816200 |
| 29 | 1 |
| 30 | 1163381400 |
| 31 | 1 |
| 32 | 4808643120 |
| 33 | 1 |
| 34 | 19835652870 |
| 35 | 1 |
| 36 | 81676217700 |
| 37 | 1 |
| 38 | 335780006100 |
| 39 | 1 |
| 40 | 1378465288200 |
| 41 | 1 |