for i = 1 to 20
    print i; " = "; factorial$(i)
next i
end

function factorial$ (num)
    factor$ = "" : x$ = ""
    if num = 1 then return "1"
    fct = 2
    while fct <= num
        if (num mod fct) = 0 then
            factor$ += x$ + string(fct)
            x$  = " x "
            num /= fct
        else
            fct += 1
        end if
    end while
    return factor$
end function