You need the greatest common divisor:

Returns the greatest common divisor of two or more integers. The greatest
common divisor is the largest integer that divides both number1 and number2
without a remainder.

If this function is not available, and returns the #NAME? error, install and
load the Analysis ToolPak add-in.

See Excel Help fo examples
--
Gary's Student


"Mnta1981" wrote:

I was wondering if there is a function in Excel that would help me find
patterns in a given set of numbers. For a very simple instance, the number
set pattern for 3,6,9,12,15,18 is obiviously three. Thanks.