Why are the EVEN grid numbers ALWAYS ÷4 and the ODDS NEVER PRIME? 

EVENS ÷4

ALL Inner Grid (IG) EVENS are ÷4 as the ∆ in PDs (ODD-ODD=EVEN, EVEN-EVEN=EVEN) ALWAYS results in an EVEN÷4. That is a result of the SQUARE of ANY EVEN # = EVEN ÷4.

ODDS = Not-PRIME (NP)

ALL Strict Inner Grid (SIG = IG - 1^st Parallel Diagonal of ODDs: 3-5-7-9-11-13…) #s are NOT PRIME (ODD-EVEN=ODD, EVEN-ODD=ODD) because they are ALL multiples of the ODD #s of the 1^st Parallel Diagonal . The ODDs of the 3^rd Parallel Diagonal are ÷3, the 5^th ÷5, the 7^th ÷7,…

ALL SIG ODDs, as the ∆ in PDs, are NOT PRIME because only the ∆ in an adjacent ODD or EVEN PD can generate a PRIME and these are ONLY on the 1^st Parallel Diagonal (containing ALL the ODDs ≥3):

• e.i. (PD=49) - (PD=36) = 13, a PRIME, as (√49=7) - (√36=6) = 1, landing the 13 PRIME on the 1^st Parallel Diagonal, whereas (PD=49) - (PD=16) = 33 (or 3x11), as (√49) - (√16) = 7 -4 = 3, as 33 lands on the 3^rd Parallel Diagonal. 

• Note that the 1^st Parallel Diagonal contains ALL the ODDS (PvsNP) and some adjacent PD ∆s will put you there, as (PD=25) - (PD=16) = 9, as (√25) - (√16) = 1.

• The KEY POINT is that ONLY ADJACENT AXIS #s — whose ∆ = 1 — can, when SQUARED and placed on the PD, generate PRIMES by taking their differences (∆s).