FACTDOUBLE

Giai thừa kép n!! (cách quãng 2). FACTDOUBLE(value)

Cú pháp: =FACTDOUBLE(value)

Ví dụ

• 7 × 5 × 3 × 1: =FACTDOUBLE(7)
• 6!! = 6 × 4 × 2: =FACTDOUBLE(6)