Excel functions

How to Use the FACTDOUBLE Function in Excel

Today, let’s delve into a highly useful mathematical function available in both Microsoft Excel and Google Sheets – FACTDOUBLE. This function calculates the double factorial of a number. A double factorial of a number n, denoted as n!!, is the product of all integers from 1 to n that share the same parity (either all odd or all even).

Syntax:

The syntax for the FACTDOUBLE function is identical in Microsoft Excel and Google Sheets:

=FACTDOUBLE(number)

Examples:

To clarify how this function is used, let’s examine a few examples:

Example 1:

Calculate the double factorial for the number 5.

Excel Formula Result
=FACTDOUBLE(5) 15

Here, 5!! = 5 × 3 × 1 = 15.

Example 2:

Calculate the double factorial for the number 6.

Excel Formula Result
=FACTDOUBLE(6) 48

For this instance, 6!! = 6 × 4 × 2 = 48.

Example 3:

Employ the FACTDOUBLE function in a more complex formula.

Imagine we want to calculate the sum of double factorials from 1 to 5.

Excel Formula Result
=SUM(FACTDOUBLE(ROW(1:5))) 49

In this scenario, we first generate an array {1, 2, 3, 4, 5} using the ROW function, calculate the double factorial for each element of the array, then sum these values to obtain 49.

As the examples illustrate, the FACTDOUBLE function is an essential and versatile tool in both Excel and Google Sheets for computing double factorials and for its integration into more elaborate formulas.

More information: https://support.microsoft.com/en-us/office/factdouble-function-e67697ac-d214-48eb-b7b7-cce2589ecac8

Other functions
ABS
Returns the absolute value of a number
ACOS
Returns the arccosine of a number
ACOSH
Returns the inverse hyperbolic cosine of a number
ACOT
Returns the arccotangent of a number
ACOTH
Returns the hyperbolic arccotangent of a number
AGGREGATE
Returns an aggregate in a list or database
ARABIC
Converts a Roman number to Arabic, as a number
ASIN
Returns the arcsine of a number
ASINH
Returns the inverse hyperbolic sine of a number
ATAN
Returns the arctangent of a number
ATAN2
Returns the arctangent from x- and y-coordinates
ATANH
Returns the inverse hyperbolic tangent of a number
BASE
Converts a number into a text representation with the given radix (base)
CEILING
Rounds a number to the nearest integer or to the nearest multiple of significance
CEILING.MATH
Rounds a number up, to the nearest integer or to the nearest multiple of significance
CEILING.PRECISE
Rounds a number the nearest integer or to the nearest multiple of significance Regardless of the sign of the number, the number is rounded up
COMBIN
Returns the number of combinations for a given number of objects
COMBINA
Returns the number of combinations (with repetitions) for a given number of items
COS
Returns the cosine of a number
COSH
Returns the hyperbolic cosine of a number
COT
Returns the hyperbolic cosine of a number
COTH
Returns the cotangent of an angle
CSC
Returns the cosecant of an angle
CSCH
Returns the hyperbolic cosecant of an angle
DECIMAL
Converts a text representation of a number in a given base into a decimal number
DEGREES
Converts radians to degrees
EVEN
Rounds a number up to the nearest even integer
EXP
Returns
FACT
Returns the factorial of a number
FLOOR.MATH
Rounds a number down, to the nearest integer or to the nearest multiple of significance
FLOOR.PRECISE
Rounds a number the nearest integer or to the nearest multiple of significance Regardless of the sign of the number, the number is rounded up
GCD
Returns the greatest common divisor
INT
Rounds a number down to the nearest integer
ISO.CEILING
Returns a number that is rounded up to the nearest integer or to the nearest multiple of significance
LCM
Returns the least common multiple
LET
Assigns names to calculation results to allow storing intermediate calculations, values, or defining names inside a formula
LN
Returns the natural logarithm of a number
LOG
Returns the logarithm of a number to a specified base
LOG10
Returns the base-10 logarithm of a number
MDETERM
Returns the matrix determinant of an array
MINVERSE
Returns the matrix inverse of an array
MMULT
Returns the matrix product of two arrays
MOD
Returns the remainder from division
MROUND
Returns a number rounded to the desired multiple
MULTINOMIAL
Returns the multinomial of a set of numbers
MUNIT
Returns the unit matrix or the specified dimension
ODD
Rounds a number up to the nearest odd integer
PI
Returns the value of pi
POWER
Returns the result of a number raised to a power
PRODUCT
Multiplies its arguments
QUOTIENT
Returns the integer portion of a division
RADIANS
Converts degrees to radians
RAND
Returns a random number between 0 and 1
RANDARRAY
Returns an array of random numbers between 0 and 1 However, you can specify the number of rows and columns to fill, minimum and maximum values, and whether to return whole numbers or decimal values
RANDBETWEEN
Returns a random number between the numbers you specify
ROMAN
Converts an arabic numeral to roman, as text
ROUND
Rounds a number to a specified number of digits
ROUNDDOWN
Rounds a number down, toward zero
ROUNDUP
Rounds a number up, away from zero
SEC
Returns the secant of an angle
SECH
Returns the hyperbolic secant of an angle
SEQUENCE
Generates a list of sequential numbers in an array, such as 1, 2, 3, 4
SERIESSUM
Returns the sum of a power series based on the formula
SIGN
Returns the sign of a number
SIN
Returns the sine of the given angle
SINH
Returns the hyperbolic sine of a number
SQRT
Returns a positive square root
SQRTPI
Returns the square root of (number * pi)
SUBTOTAL
Returns a subtotal in a list or database
SUM
Adds its arguments
SUMIF
Adds the cells specified by a given criteria
SUMIFS
Adds the cells in a range that meet multiple criteria
SUMPRODUCT
Returns the sum of the products of corresponding array components
SUMSQ
Returns the sum of the squares of the arguments
SUMX2MY2
Returns the sum of the difference of squares of corresponding values in two arrays
SUMX2PY2
Returns the sum of the sum of squares of corresponding values in two arrays
SUMXMY2
Returns the sum of squares of differences of corresponding values in two arrays
TAN
Returns the tangent of a number
TANH
Returns the hyperbolic tangent of a number
TRUNC
Truncates a number to an integer