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 | 6 |
| 4 | 6 |
| 5 | 30 |
| 6 | 10 |
| 7 | 70 |
| 8 | 70 |
| 9 | 210 |
| 10 | 168 |
| 11 | 1848 |
| 12 | 1848 |
| 13 | 18018 |
| 14 | 8580 |
| 15 | 2574 |
| 16 | 2574 |
| 17 | 102102 |
| 18 | 102102 |
| 19 | 831402 |
| 20 | 2771340 |
| 21 | 3233230 |
| 22 | 587860 |
| 23 | 43266496 |
| 24 | 117630786 |
| 25 | 162249360 |
| 26 | 145088370 |
| 27 | 145088370 |
| 28 | 2897310 |
| 29 | 672175920 |
| 30 | 672175920 |
| 31 | 18232771830 |
| 32 | 18232771830 |
| 33 | 44279588730 |
| 34 | 8886561060 |