If M(n) is the n-th Mersenne prime, then a(n) is the smallest positive integer such that 2*a(n)*M(n)*M(n+1)*M(n+2)-1 is prime.

A093192

If M(n) is the n-th Mersenne prime, then a(n) is the smallest positive integer such that 2*a(n)*M(n)*M(n+1)*M(n+2)-1 is prime.

Terms

    a(0) =1a(1) =1a(2) =21a(3) =1a(4) =12a(5) =16a(6) =6a(7) =112a(8) =76a(9) =195a(10) =61a(11) =21a(12) =511a(13) =909a(14) =1689a(15) =517a(16) =640a(17) =487a(18) =13615a(19) =12547a(20) =382a(21) =60456

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