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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.
3
1, 53, 11, 17, 317, 89, 737, 2543, 1247, 6209, 15107, 33119, 60611, 671063, 2648057
OFFSET
1,2
EXAMPLE
(2^2-1)*(2^2-1+1)-1=11 prime, 11 and 13 twin primes, 2^2-1=M(1) so a(1)=1
CROSSREFS
Cf. A139426.
Sequence in context: A078681 A143294 A143428 * A231426 A298061 A297984
KEYWORD
hard,more,nonn
AUTHOR
Pierre CAMI, Aug 11 2008
STATUS
approved