26189

Properties

Appears in sequences

• Primes that remain prime through 3 iterations of the function f(x) = 2*x + 1.at n=19A023272
• Least prime in A031932 (lesser of 14-twins) whose distance to the next 14-twin is 6*n.at n=25A052356
• Fourth term of balanced prime quartets: p(m-2)-p(m-3) = p(m-1)-p(m-2) = p(m)-p(m-1).at n=16A054803
• Primes starting a Cunningham chain of the first kind of length 4.at n=14A059763
• Primes p that have exactly three primitive roots that are not primitive roots mod p^2.at n=10A060519
• Numbers n such that n, 2n+1, 3n+2, 4n+3 are primes.at n=12A067257
• Values that show the slow decrease in the Andrica function Af(k) = sqrt(p(k+1)) - sqrt(p(k)), where p(k) denotes the k-th prime.at n=27A084977
• Smallest primes starting a complete three iterations Cunningham chain of the first or second kind.at n=23A110025
• Smaller of 3 consecutive prime numbers such that p1*p2*p3+d1+d2-1=average of twin prime pairs, d1(delta)=p2-p1,d2(delta)=p3-p2.at n=10A153402
• Primes of the Form : p1=a*b+c;p2=a*c+b;p3=b*c+a;p=(p1+p2+p3)/2; p1,p2 and p3 are three consecutive prime numbers.at n=6A157722
• Primes p such that 2*p^3-+15 are also prime.at n=34A174364
• Number of 0..n arrays of length 3 with each element differing from at least one neighbor by something other than 1.at n=29A221574
• Primes q = 4*p+1, where p == 2 (mod 5) is also prime.at n=43A221981
• Number of (n+1) X (1+1) 0..2 arrays with the minimum plus the maximum equal to the lower median plus the upper median in every 2 X 2 subblock.at n=5A235895
• Number of (n+1)X(6+1) 0..2 arrays with the minimum plus the maximum equal to the lower median plus the upper median in every 2X2 subblock.at n=0A235900
• T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with the minimum plus the maximum equal to the lower median plus the upper median in every 2X2 subblock.at n=15A235902
• T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with the minimum plus the maximum equal to the lower median plus the upper median in every 2X2 subblock.at n=20A235902
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 627", based on the 5-celled von Neumann neighborhood.at n=28A273276
• Primes equal to a centered heptagonal number plus 1.at n=17A285811
• Least number that reaches 1 after exactly n iterations of the infinitary analog of the totient function A384247.at n=19A385747