19709

Properties

Appears in sequences

• Primes that remain prime through 3 iterations of the function f(x) = 2*x + 1.at n=16A023272
• a(n) = s(1)s(n) + s(2)s(n-1) + ... + s(k)s(n-k+1), where k = [ n/2 ], s = A000201 (lower Wythoff sequence).at n=43A025118
• Primes starting a Cunningham chain of the first kind of length 4.at n=11A059763
• a(n) is the smallest prime of the form n^k + n - 1 with k >= 2.at n=25A078179
• Smallest prime of the form n^j+(n+1)^k, with j,k integer > 0, max(j,k)>1.at n=25A093575
• Value of C in y = x^2+7x+C such that y is prime for all x = 0 to 4.at n=26A097436
• Primes p such that 2p+1, 4p+3, 6p+5 are all primes.at n=19A107020
• Primes p such that 2p+1, 4p+3, 6p+5, 8p+7 are all primes.at n=3A107021
• Smallest primes starting a complete three iterations Cunningham chain of the first or second kind.at n=17A110025
• Numbers n such that f(n), f(n+1) and f(n+2) are prime, f(m)=72*m^2+7.at n=21A121089
• Primes congruent to 3 mod 59.at n=38A142730
• Primes congruent to 6 mod 61.at n=35A142804
• Primes of the form ((p+1)/2)^3 + ((p-1)/2), p is prime.at n=7A163426
• Numbers starting with 1 such that the sum of any two distinct elements has an even number of distinct prime factors.at n=14A180514
• Primes of the form n^3 + n - 1.at n=9A182332
• Number of 7Xn -1,1 arrays such that the sum over i=1..7,j=1..n of i*x(i,j) is zero, the sum of x(i,j) is zero, and rows are nondecreasing (number of ways to distribute n-across galley oarsmen left-right at 7 fore-aft positions so that there are no turning moments on the ship).at n=9A225347
• Primes of the form 3^k + 3^m - 1, where k and m are positive integers.at n=20A234346
• Primes of the form m = 3^i + 3^j - 1, where i > j >= 0.at n=16A239713
• Primes of the form 3^k + 26.at n=5A243439
• Primes p such that p minus its digit sum is a perfect cube.at n=18A245064