Function to return the nth term of the required sequence
def nth_term ( a , b , n ) : NEW_LINE INDENT z = 0 NEW_LINE if ( n % 6 == 1 ) : NEW_LINE INDENT z = a NEW_LINE DEDENT elif ( n % 6 == 2 ) : NEW_LINE INDENT z = b NEW_LINE DEDENT elif ( n % 6 == 3 ) : NEW_LINE INDENT z = b - a NEW_LINE DEDENT elif ( n % 6 == 4 ) : NEW_LINE INDENT z = - a NEW_LINE DEDENT elif ( n % 6 == 5 ) : NEW_LINE INDENT z = - b NEW_LINE DEDENT if ( n % 6 == 0 ) : NEW_LINE INDENT z = - ( b - a ) NEW_LINE DEDENT return z NEW_LINE DEDENT