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) |
|---|---|
| 3 | 756 |
| 4 | 4128 |
| 5 | 18240 |
| 6 | 73368 |
| 7 | 277536 |
| 8 | 1001760 |
| 9 | 3512160 |
| 10 | 12009480 |
| 11 | 40390944 |
| 12 | 133893936 |
| 13 | 439304736 |
| 14 | 1428450072 |
| 15 | 4613176800 |
| 16 | 14809528896 |
| 17 | 47315578848 |
| 18 | 150534443304 |
| 19 | 477237381024 |
| 20 | 1508232832080 |
| 21 | 4753573999776 |
| 22 | 14945425070136 |
| 23 | 46886868887136 |
| 24 | 146802927436128 |
| 25 | 458818252975200 |