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A050821 Even numbers in the sequence generated by a(n)=|a(n-1)+2a(n-2)-n| where a(0)=a(1)=1. 1

%I

%S 0,2,0,6,0,2,8,6,8,10,10,8,14,0,0,26,4,18,8,14,18,20,20,18,28,14,12,

%T 26,44,14,26,24,38,16,10,32,22,32,64,10,36,38,22,36,64,10,24,14,6,24,

%U 38,44,74,28,36,50,92,14,52,50,46,56,72,38,24,106,6,68,30,0,80,58,42,20,4

%N Even numbers in the sequence generated by a(n)=|a(n-1)+2a(n-2)-n| where a(0)=a(1)=1.

%t nxt[{n_,a_,b_}]:={n+1,b,Abs[b+2a-n-1]}; Select[NestList[nxt,{1,1,1},200][[All,2]],EvenQ] (* _Harvey P. Dale_, Aug 25 2022 *)

%Y Cf. A005210.

%Y Equals 2*A039727(n).

%K nonn,easy

%O 1,2

%A _Mohammad K. Azarian_

%E More terms from _James A. Sellers_

%E Definition clarified by _Harvey P. Dale_, Aug 25 2022

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Last modified February 5 09:10 EST 2023. Contains 360082 sequences. (Running on oeis4.)