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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 90 |
| 6 | 540 |
| 7 | 1995 |
| 8 | 5775 |
| 9 | 14280 |
| 10 | 31500 |
| 11 | 63630 |
| 12 | 119790 |
| 13 | 212850 |
| 14 | 360360 |
| 15 | 585585 |
| 16 | 918645 |
| 17 | 1397760 |
| 18 | 2070600 |
| 19 | 2995740 |
| 20 | 4244220 |
| 21 | 5901210 |
| 22 | 8067780 |
| 23 | 10862775 |
| 24 | 14424795 |
| 25 | 18914280 |
| 26 | 24515700 |
| 27 | 31439850 |
| 28 | 39926250 |
| 29 | 50245650 |
| 30 | 62702640 |
| 31 | 77638365 |
| 32 | 95433345 |
| 33 | 116510400 |