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) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 21 |
| 3 | 75 |
| 4 | 105 |
| 5 | 315 |
| 6 | 495 |
| 7 | 945 |
| 8 | 1575 |
| 9 | 2835 |
| 10 | 3465 |
| 11 | 4095 |
| 12 | 11025 |
| 13 | 17955 |
| 14 | 10395 |
| 15 | 23205 |
| 16 | 17325 |
| 17 | 24255 |
| 18 | 31185 |
| 19 | 36855 |
| 20 | 51975 |
| 21 | 61425 |
| 22 | 45045 |
| 23 | 108675 |
| 24 | 143325 |
| 25 | 121275 |
| 26 | 184275 |
| 27 | 155925 |
| 28 | 135135 |
| 29 | 176715 |
| 30 | 239085 |
| 31 | 315315 |
| 32 | 294525 |
| 33 | 225225 |
| 34 | 606375 |
| 35 | 626535 |
| 36 | 405405 |
| 37 | 700245 |
| 38 | 1531530 |
| 39 | 1351350 |
| 40 | 2072070 |
| 41 | 1289925 |
| 42 | 855855 |