How many arrangements of the numbers 1,2,3,...,7 are there where the sum of any two adjacent numbers is odd?
for this, we would have to swap between odd and even numbers for the arrangement, so
4x3x3x2x2+4x3x3x2x2+4x3x3x2x2+4x3x3x2+4x3x3+4x3=$\boxed{552}$