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) |
|---|---|
| 14 | 1 |
| 15 | 15 |
| 16 | 120 |
| 17 | 680 |
| 18 | 3060 |
| 19 | 11628 |
| 20 | 38760 |
| 21 | 116280 |
| 22 | 319770 |
| 23 | 817190 |
| 24 | 1961256 |
| 25 | 4457400 |
| 26 | 9657700 |
| 27 | 20058300 |
| 28 | 40116600 |
| 29 | 77558760 |
| 30 | 145422675 |
| 31 | 265182525 |
| 32 | 471435600 |
| 33 | 818809200 |
| 34 | 1391975640 |
| 35 | 2319959400 |
| 36 | 3796297200 |
| 37 | 6107086800 |
| 38 | 9669554100 |
| 39 | 15084504396 |
| 40 | 23206929840 |
| 41 | 35240152720 |