Doppler puzzle

[John Delmore]

Hi Vladen--
Did I learn, incorrectly, that "1 cent" is defined as one one-hundredth of
the Hz difference between one note and an adjacent semi-tone?  Or, are the
cents "tempered"?  In the first case, the value of each cent is constant
between semi-tones, i.e. one cent above a tone is equal in Hz to the cent
below the next semi-tone.  In the second case, the "first" cent is not equal
in Hz to the "last" cent. I'm a newbie with more mathematical sense than
piano sense, so I just want to get it right!!
JD