How to do it...

To implement this recipe, perform the following steps:

1. Create the following column in the R08_Calendar table:

SequentialWeek = 
    VAR __Date = 'R08_Calendar'[Date] // The working date, edit if column is not Date
    VAR __Year = YEAR(__Date) // Get the working date 
    VAR __Calendar = // Create calendar table with year and weeknum
        ADDCOLUMNS(
            ALL('R08_Calendar'), // Edit table name to match
            "__Year",
            YEAR('R08_Calendar'[Date]), // Edit table and column to match
            "__WeekNum",
            WEEKNUM('R08_Calendar'[Date]) // Edit table and column to match
        )
    VAR __FirstYear = MINX(__Calendar,[__Year]) // Determine the first year in our table
    VAR __WeekNum = // Get the current working week number
        MAXX(
            FILTER(
                __Calendar,
                [Date] = __Date
            ),
            [__WeekNum]
        )
    VAR __MaxWeeks = // Create a table of years and their max week numbers
        GROUPBY(
            __Calendar,
            [__Year],
            "__MaxWeek",
            MAXX(
                CURRENTGROUP(),
                [__WeekNum]
            )
        )
    VAR __Start = // Use __MaxWeeks table to get starting point for week number 
        SUMX(
            FILTER(
                __MaxWeeks,
                [__Year]<__Year
            ),
            [__MaxWeek]
        )
    VAR __Sequential = 
        IF(
            __Year=__FirstYear,
            __WeekNum, // If first year, then just the week number
            __Start + __WeekNum // Otherwise, __Start + current week number
        )
RETURN __Sequential