26557

Properties

Appears in sequences

• Primes that remain prime through 4 iterations of function f(x) = 9x + 4.at n=13A023325
• Number of n X 2 arrays of the minimum value of corresponding elements and their horizontal or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..3 n X 2 array.at n=10A219708
• Primes formed from concatenation of PrimePi(n) and prime(n).at n=33A236551
• Primes p such that 10p + 1, 100p + 1 and 1000p + 1 are also primes.at n=26A243962
• a(n) = smallest prime q such that Sum_{primes p <= q} 1/sqrt(p) >= n.at n=41A292775
• Number of nX3 0..1 arrays with every element unequal to 0, 1, 2, 4, 7 or 8 king-move adjacent elements, with upper left element zero.at n=9A316540
• Numbers k such that there are exactly four biquadratefree powerful numbers (A338325) between k^2 and (k+1)^2.at n=23A338391
• 2*a(n) is the start of 3 consecutive numbers (even-odd-even) that are sums of divisors, i.e., terms of A000203.at n=45A342555
• Primes p whose reverse q is a semiprime, and of p+q and its reverse one is a prime and the other is a semiprime.at n=34A350781
• Numbers k such that 30*k - 1, 30*k + 1, 30*k^2 - 1 and 30*k^2 + 1 are all prime.at n=37A359184
• Lesser of 2 successive primes (k, k+4) sandwiching 3 consecutive nonsquarefree numbers.at n=17A366352
• Primes having only {2, 5, 6, 7} as digits.at n=37A386160
• Prime numbersat n=2914