In this project, we use the phrase *periodic sequence* to refer to a
sequence that gives rise to a periodic waveform.
Such sequences are those sequences A={a_{n}} with the property that
there exists a P such that *n* is in *A* if and only iff *n*+*P* is in *A*.
One class of such sequences are those of the form a_n = mn, where m is a positive integer
(for example, if m=4, then the sequence begins 4, 8, 12, 16, 20, ...).
The waveform for such a sequence
can be analysed with fourier methods (see here).
The waveform will have fundamental frequency 44100/m hz, and the spectrogram will
exhibit spectral lines at every integer multiple of 44100/m.

For example, this is the spectrogram for the waveform made with m=11, showing the fundamental at 44100/11=4009.09... hz, and the four harmonics below 22050 hz.

In practice, only multiples of the fundamental less than 44100/2 = 22050 need to be considered: the waveform generated with this subset of harmonis will be audibly indistinguishable from the actual waveform.