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A164921 a(1)=0, a(2)=1. For n >=3, a(n) = the smallest integer > a(n-1) that is coprime to every sum of any two distinct earlier terms of this sequence. 2

%I

%S 0,1,2,5,11,17,23,29,37,41,47,53,59,67,71,79,83,89,97,101,107,113,127,

%T 131,137,149,157,163,167,173,179,191,197,211,223,227,233,239,251,257,

%U 263,269,277,281,293,307,311,317,331,337,347,353,359,367,373,379,383

%N a(1)=0, a(2)=1. For n >=3, a(n) = the smallest integer > a(n-1) that is coprime to every sum of any two distinct earlier terms of this sequence.

%e The first 4 terms are 0,1,2,5. The sums of every pair of distinct terms are: 0+1=1, 0+2=2, 1+2=3, 0+5=5, 1+5=6, and 2+5=7. So we are looking for the smallest integer >5 that is coprime to 1, 2, 3, 5, 6, and 7. This number, which is a(5), is 11.

%Y A164901, A164922, A164923

%K nonn

%O 1,3

%A _Leroy Quet_, Aug 31 2009

%E More terms. _Sean A. Irvine_, Sep 15 2009

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Last modified October 26 18:30 EDT 2021. Contains 348268 sequences. (Running on oeis4.)