30987

Appears in sequences

• Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 32.at n=10A031710
• Numbers k such that sigma(k-phi(k)) = phi(k).at n=13A070170
• a(n) = 121*n^2 + 11.at n=16A158536
• Numbers k such that the product of the first k primes minus the (k+1)-th prime is prime.at n=21A249798