The search for regularities in the background for the genetic code and its codon assignments is here further developed, earlier shown to have many correlations with numeral series of integers 5 →0 with different exponents. The atomic mass analysis here counts on 20 + 4 double-coded amino acids, here including Ile AUA as such. A central finding here is that the C-skeleton seems to build on an hierarchical development of the mentioned basic series giving top numbers equal to those returning in side-chain divisions and on first three levels those of C-atoms in base-pair domains. It can very elementary explain the 3/2-division in the weight series. A few main results from earlier articles are shortly recapitulated, since it’s shown here that an x3-series times 15 (x = integers 5 → 0) joins those earlier aspects and add new ones. It’s found also that atoms with valences 4 + 3 relative those with 2 + 1 make up a 3 to 1-division in both base-pair groups of codon domains, strengthening the earlier observation of valences as one important guiding principle in the relation between codons and domains of amino acids; valences of the atoms which in themselves make up a basic series 5 → 0 in the code when phosphorus P is included. Finally, fundamental factors in the code are gathered, where step 4 →3 seems reign at bottom of the code and number 7, exactly mean value of all atoms.