Count Sequences with Non Duplicate Entries

"""
A brute-force method to calculate status LED color sequences where colors do not repeat consecutively.
ayush@tesseract.in
"""

def cartesianProduct(lists):
    '''Returns cartesian product of lists (operands) in the given list of operands)'''
    if lists == []: return [[]]
    return [x + [y] for x in cartesianProduct(lists[:-1]) for y in lists[-1]]

def countDuplicateSequences(colorList, sequenceLength):
    '''Prints no. of sequences where entries are non-repeating'''

    count = 0
    i = 0
    operandList = []

    for i in range(sequenceLength):
        operandList.append(colorList)

    allSequences = cartesianProduct(operandList)

    for sequence in allSequences:
        for i in range(sequenceLength-1):
            if sequence[i]==sequence[i+1]:
                count += 1
#               print sequence

    print 'Total count = ' + str(len(allSequences))
    print 'Duplicates = ' + str(count)
    print 'Non duplicate count = ' + str(len(allSequences) - count)

countDuplicateSequences(['R','G','B','C','M','Y','W'], 4)