The noise is updated every sample.
+ The noise is updated every second sample
+ The noise is updated every fourth sample.
+ The noise is updated every fourth sample.
+ The noise is updated every sixteenth sample.
= The output of the pink noise generator is the sum of N rows, numbering 0 to N-1.
so that's N different noise source running at N diadically spaced rates, fs, fs/2, fs/4, fs/8, etc...
also, "Note that there is a small amount of ripple (about 1dB) which does not go away regardless of the number of rows added. ", which itself could probably be improved if the something other than the zero-order-hold kernel was used.