3221225473

Appears in sequences

• a(0) = 1; thereafter a(n) = 3*2^(n-1) + 1.at n=31A004119
• Smallest prime of form 2^n*k + 1.at n=28A035089
• Smallest prime of form 2^n*k + 1.at n=29A035089
• Smallest prime of form 2^n*k + 1.at n=30A035089
• Primes of the form 3*2^k + 1.at n=7A039687
• Minimal 2^n safe-primes: a(n) = 2^n*A051886(n) + 1 (a prime number).at n=30A051900
• a(n) is the least prime p such that p-1 is divisible by 2^n and not by 2^(n+1).at n=30A057775
• Smallest term x from A066669 such that phi(x) = 2^n times some prime.at n=29A066673
• Primes p such that cototient(totient(p)) = A070556(p) is a power of 2.at n=25A070806
• Smallest prime which is 1 more than the product of n (not necessarily distinct) composite numbers.at n=15A081546
• Duplicate of A051900.at n=30A084706
• Smallest prime with exactly n consecutive zeros in the longest run of zeros in its binary expansion.at n=29A090587
• Expansion of g.f.: (3+x+2*x^2-2*x^3)/((1-2*x)*(1+x^2)).at n=30A100720
• a(1) = 2, a(2) = 4; a(n) = 2*a(n-1) - 1.at n=31A103204
• a(n) = 3*4^n + 1.at n=15A140660
• a(n) = smallest prime p such that p-1 and p+1 together have n prime divisors, or a(n) = 0 if no such prime exists.at n=33A155800
• a(n) = 3*2^n + 1.at n=30A181565
• a(n) = 3*8^n + 1.at n=10A199494
• Half the number of (n+1) X 3 0..2 arrays with every 2 X 2 subblock having exactly two distinct clockwise edge differences.at n=19A209530
• Half the number of (n+1) X 7 0..2 arrays with every 2 X 2 subblock having exactly two distinct clockwise edge differences.at n=7A209532