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(1, 2, 3, 2^2, 5, 2*3, 7, 2^3, 3^2, 2*5, 11, 2^2*3, 13, 2*7, 3*5,..) becomes (abs(1-2-3-2, 2-5-2-3, 7-2-3-3, 2-2-5-11, 2-2-3-13, 2-7-3-5,..)).
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%I #10 Apr 26 2016 00:15:17

%S 6,8,1,16,16,13,21,20,13,34,7,17,36,37,17,27,5,13,3,29,28,6,30,8,17,

%T 66,9,1,47,52,89,8,14,77,41,81,6,31,1,1,91,8,124,13,31,13,82,17,55,69,

%U 103,10,13,100,119,18,155,6,91,40,111,11,32,55,9,10,15,37,10,115,23,124,17

%N (1, 2, 3, 2^2, 5, 2*3, 7, 2^3, 3^2, 2*5, 11, 2^2*3, 13, 2*7, 3*5,..) becomes (abs(1-2-3-2, 2-5-2-3, 7-2-3-3, 2-2-5-11, 2-2-3-13, 2-7-3-5,..)).

%H Robert Israel, <a href="/A143852/b143852.txt">Table of n, a(n) for n = 1..10000</a>

%e Abs (2-7-3-5)=abs (-13) =13=a(6).

%e Abs (2-4-17-2)=abs(-21)=21=a(7).

%e Abs (3-2-19-2)=abs (-20)=20=a(8).

%e Abs (2-5-3-7)=abs (-13)=13=a(9).

%e Abs (2-11-23-2)=abs(-34)=34=a(10),

%e etc.

%p g:= proc(n) local F;

%p F:= sort(ifactors(n)[2], (a,b) -> a[1]<b[1]);

%p op(subs(1=NULL,map(op,F)));

%p end proc:

%p g(1):= 1:

%p L:= map(g, [$1..300]):

%p seq(abs(L[i]-L[i+1]-L[i+2]-L[i+3]),i=1..nops(L)-3,4); # _Robert Israel_, Apr 25 2016

%t Abs@ Total@ MapAt[Abs, Minus@ #, {1}] & /@ Partition[#, 4] &@ Flatten[FactorInteger /@ Range@ 134 /. {a_, b_} /; b == 1 :> {a}] (* _Michael De Vlieger_, Apr 25 2016 *)

%Y Cf. A141287, A141261, A136678, A143717.

%K nonn

%O 1,1

%A _Juri-Stepan Gerasimov_, Nov 17 2008

%E Corrected (10 replaced by 8) and extended by _R. J. Mathar_, Apr 18 2010