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 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 17788848 |
| 5 | 36105677160 |
| 6 | 9840227891760 |
| 7 | 838876379282760 |
| 8 | 33316659511111200 |
| 9 | 770358326829901488 |
| 10 | 11901952345453621920 |
| 11 | 134595078267062009520 |
| 12 | 1187095862662143754320 |
| 13 | 8549491024060638451800 |
| 14 | 52035271347355128360528 |
| 15 | 274779269587463677316280 |