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 | 3 |
| 2 | 36 |
| 3 | 300 |
| 4 | 1485 |
| 5 | 3240 |
| 6 | 265356 |
| 7 | 265356 |
| 8 | 21520080 |
| 9 | 21520080 |
| 10 | 193720086 |
| 11 | 1743362676 |
| 12 | 141214502520 |
| 13 | 141214502520 |
| 14 | 11438393835996 |
| 15 | 11438393835996 |
| 16 | 926510072902560 |
| 17 | 926510072902560 |
| 18 | 75047317454789316 |
| 19 | 75047317454789316 |
| 20 | 6078832727785072200 |
| 21 | 6078832727785072200 |