Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
Arguably, I would say that in this case 6 is the magic number ..
Stranding is based on the recognition that for circles of equal diameter, 6 will almost exactly fill the space around 1; next, one can see, that 12 fill the space around 6, 18 around 12, and so on ..
So, one needs to add 6 to the number in the outer ring each time to fill the next ring ..