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A099478 Least a(n) such that a(n)*2^n*(2^n-1)-1 is prime. 0

%I

%S 2,1,3,1,1,4,3,6,1,1,4,2,9,4,9,14,4,1,3,4,36,5,25,4,10,4,18,3,21,9,9,

%T 21,16,65,12,8,51,1,22,2,30,6,10,63,1,30,15,3,10,1,22,57,202,4,3,53,1,

%U 34,12,10,22,29,28,31,7,6,70,29,16,94,37,51,30,56,19,23,70,50,99,16,34,5

%N Least a(n) such that a(n)*2^n*(2^n-1)-1 is prime.

%e 1*2^6*(2^6-1)-1=4031=29*139

%e 2*2^6*(2^6-1)-1=8063=11*733

%e 3*2^6*(2^6-1)-1=12095=5*2419

%e 4*2^6*(2^6-1)-1=16127 prime so a(6)=4

%K easy,nonn

%O 1,1

%A _Pierre CAMI_, Nov 18 2004

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Last modified November 16 17:04 EST 2019. Contains 329201 sequences. (Running on oeis4.)