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A168629 Numbers n such that n,n+1 and sum of this two numbers have 3 distinct prime factors. 1

%I

%S 1105,1130,1462,1644,1742,1767,2014,2222,2232,2260,2337,2365,2397,

%T 2464,2541,2667,2684,2697,2702,2755,2821,2914,3074,3115,3195,3289,

%U 3332,3477,3484,3514,3552,3619,3657,3685,3782,3783,3842,3965,4014,4088,4122,4147

%N Numbers n such that n,n+1 and sum of this two numbers have 3 distinct prime factors.

%e FactorInteger[1105]=5*13*17, FactorInteger[1106]=2*7*79, FactorInteger[1105+1106]=3*11*67,..

%t f[n_]:=Length[FactorInteger[n]]; lst={};Do[If[f[n]>=3&&f[n+1]>=3&&f[n+n+1]>=3,AppendTo[lst,n]],{n,8!}];lst

%Y Cf. A140077, A140078, A168626, A168628

%K nonn

%O 1,1

%A _Vladimir Joseph Stephan Orlovsky_, Dec 01 2009

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Last modified November 22 18:55 EST 2019. Contains 329410 sequences. (Running on oeis4.)