I am so pleased others are finding this work and expanding on it. There really is so much to see about "9"
The NEYƎИ Sequence was featured on a youtube by a dear friend and he is offering his findings too. worth a look... @ https://www.youtube.com/watch?v=ooIInrpvwEQ#t=0

Using an example found here with terminal digits I investigated ;

     alpha series  1, 3, 7, 6, 4, 9.  = 3
  +neyɘn series  1, 2, 4, 8, 7, 5   = 9
  +omega series 8, 6, 2, 3, 5, 0   = 6
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 = NEYƎИ Sequence 1, 2, 4, 8, 7, 5 = 9


Here are my findings;

alpha series; 937641 - 137649 = 799992 /9 = 88888, palindrome number, not prime. 88888 /9 = 9876.4444444444444 
The list of divisors of 88888 = 2, 41, 271

neyen series; 524871 - 124875 = 399996 /9 = 44444, palindrome number - not prime. 44444/9= 4938.22222222222222
The list of divisors of 44444 = 2, 41, 271

omega series; 862350 - 062358 = 799992 /9 = 88888, palindrome number - not prime. 88888 /9 = 9876.4444444444444
The list of divisors of 88888 = 2, 41, 271

44444 + 88888 + 44444 = 222220  not prime
The list of divisors of 222220 = 2, 5, 41, 271

222220 /9 =24691.111111

9876.44444 + 4938.22222 + 9876.44444 = 24691.11111

A footnote;  The largest prime factor of 88888888 is 137 or a (alpha)