69763

Properties

Appears in sequences

• a(n) and a(n)+4^k are primes at least for k=1,2,3,4.at n=24A049494
• a(n) = 2^n*C(n-1)-y(n), where y(n) = Sum_{i=1..n-1} (2^i*C(i-1)-y(i))*(2^(n-i)*C(n-i-1)-y(n-i)), y(0)=0, y(1)=1 and where C(i) is the i-th Catalan number.at n=7A192482
• Prime numbersat n=6916