Теория вероятности (4m-1)!/(4m-3)!
Полное решение
(4m-1)!/(4m-3)! = (4m-3)!*(4m-2)*(4m-1) / (4m-3)! = (4m-2)*(4m-1) = 16m²-8m-4m+2=16m²-12m-2