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 | 3 |
| 5 | 6 |
| 6 | 5 |
| 7 | 10 |
| 8 | 35 |
| 9 | 140 |
| 10 | 126 |
| 11 | 1260 |
| 12 | 1155 |
| 13 | 13860 |
| 14 | 12870 |
| 15 | 12012 |
| 16 | 45045 |
| 17 | 360360 |
| 18 | 340340 |
| 19 | 2042040 |
| 20 | 1939938 |
| 21 | 369512 |
| 22 | 117572 |
| 23 | 2586584 |
| 24 | 7436429 |
| 25 | 178474296 |
| 26 | 171609900 |
| 27 | 1487285800 |
| 28 | 1434168450 |
| 29 | 40156716600 |
| 30 | 38818159380 |
| 31 | 1164544781400 |