You are right, the common factor for PVK addresses is not just the difference in PVK values.

  I will tell you a mathematical relatulated.

 The PVK valalues that can be easily calculated.

 The PVK value of address 5 is 21 because address 4 has a PVK of 8, and address 5 is the next first value aft another examplell don't understand, I'll give you another examplell don't understand, I'll give you another example.  Suppose we are looking for the PVK value of address 7. We know that the PVK value of address 6 is 49.

 We understand that the PVK value of address 7 is = to the nearest prime number after 49. The next prime number after 49 is 61.

 So address 7 is at PVK 61.

 Now you understand?