83873

Properties

Appears in sequences

• Least number k such that (k*M(n))^2 + k*M(n) - 1 is prime with M(i)=i-th Mersenne prime.at n=28A121370
• Duplicate of A121370.at n=28A137908
• a(n)= least number k > a(n-1) such that k*(2^p-1)*(k*(2^p-1)+1)-1 is prime, where p = A000043(n) = Mersenne exponents.at n=28A200655
• Smallest prime k such that sigma(k - m) = sigma(k + m) has exactly n solutions, where m > 0 and sigma is A000203.at n=16A249690
• Prime numbersat n=8181