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A143385 Least a(n) such that M(n)*(M(n)+a(n))-1 and M(n)*(M(n)+a(n))+1 are twin primes with M(i)=i-th Mersenne prime. 2

%I

%S 1,53,11,17,317,89,737,2543,1247,6209,15107,33119,60611,671063,2648057

%N Least a(n) such that M(n)*(M(n)+a(n))-1 and M(n)*(M(n)+a(n))+1 are twin primes with M(i)=i-th Mersenne prime.

%e (2^2-1)*(2^2-1+1)-1=11 prime, 11 and 13 twin primes, 2^2-1=M(1) so a(1)=1

%Y Cf. Mersenne primes, A143384.

%K hard,more,nonn

%O 1,2

%A _Pierre CAMI_, Aug 11 2008

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Last modified December 4 15:36 EST 2021. Contains 349526 sequences. (Running on oeis4.)