*Ile, AU-codon, only differing in** type **of 3rd base.

**First observations:**

First to notice is that the mass sums of the two main groups with
G+C-codons and U+A-codons become the same in 1st and 2nd base order,
**544** and **960**.

It implies that mass sums of ams with mixed codons
changing position between the groups are the same, **385** (Table
2). These groups showed astonishing regularities, which seemed to
support the hypothesis that mass distribution of ams on different
codons wasn't a random one. Note the approximately equal sums horizontally
and vertically, Table 2:

**Table 2:** Mixed codons 12
amino acids, sum 385*:*

The
table is closer studied in file **The
two 12-groups of ams**.

It led to a division of the 24 codons in 2 main groups of 12 ams,
the other = 2 times **367**, (Table 3), which doesn't show the
same regularity as the other:

** ****Table
3**: Non-mixed codons. 12 amino acids, sum 734:

This way of counting and organizing codons seems deviating from
most other research.

We get 4 subgroups of codons, here called Form-, Cross-, Pair-
and RNA-codons:

Form-coded: GA, AG, UC, CU, 6 ams, sum 352

Cross-coded: GU, UG, CA, AC, 6 ams, sum 418...2 x 385 = 770

These two in Table 2.

Pair-coded: GG, CC, UU, AA, 6 ams, sum 322

RNA-coded: GC, CG, UA, AU, 6 ams, sum 412...2 x 367 = 734

These two in Table 4.

Note in Table 3:

G1 + A1, 175 + 177 =** 352**, give the same mass as the Form-coded ams,

U1 + C1, 208 + 210 = **418**, give the same mass as the Cross-coded ams.

Before going on with the analysis, two annotations:

**Survey of totals:**

With mass in unbound backbone chains (B, B-chains) à 74 A,
- 1 in the four ams Arg1 and 2, Lys and Pro. and mass 56 in bound
ams, this gives following survey of totals:

24 ams: R: **1504**, B unbound **1772**, sum **3276**
A,

24 ams: R: **1504**, B bound **1344**, sum **2848** A.

N-Z: R: **828** Z, **676** N, R+B: **1516** N, **1760**
Z, unbound ams.

Cf. for instance codon domains when we count on two sets of ams R+B, 1st plus 2nd base order, **file 17 short files, 2.6.**

**Simple variations of the elementary number chain 5-4-3-2-1-0:**

There are some simple variations of the elementary number chain
(5-4-3-2-1-0), closer dealt with in files in section II, files 12-16__,__
that more or less approximately give the division between some main
codon groups of ams, G+C and U+A, but also other more detailed ones.

Hypothetically such simpler chains on integers
5→0 with exponents 4, 1, 3, 2 could
underlie the more developed and differentiated chain in this section,
precede this in a perhaps "inflationary" evolution of
the code or represent underlying levels? Here only a couple of examples:

Reading the simple chain as **triplets** 543+432+321+210
gives 543 (G-C-group -1, U-A-group 960 +3,

**Fig 2-1:*** The triplet
series 543 - 432 etc.*

Sum
1506 = total of 20 + 4 ams R, +2.

With **exponent 4** the main division 544 - 960 (+2) derives
from first three numbers 5^{4}-4^{4}-3^{4}
plus/minus 3rd number 81: G-C-group **544 = 625 - 81**, U-A-group
960 (+2) = **625 + 256 + 81**.

With exponent 2 in the 2x^{2}-chain behind the
periodic system, times a factor 16, several different codon-groups
of ams appear (+/-1), the main division showed in figure. 2-2:

**Fig. 2-2:*** Relations
to 2x*^{2}-series, 34-26-60 times a factor 16:

Total sum of the chain, 110, times 16 = 1760, the total Z of the
24 ams (R+B).

See further file **Simpler
number chains**** **about the 2x^{2}-chain.

To **The exponent
2/3 series (ES)**