25621

Properties

Appears in sequences

• Primes that remain prime through 3 iterations of function f(x) = 8x + 5.at n=23A023293
• Smallest nontrivial extension of n-th square which is a prime.at n=15A030685
• Doubly balanced primes: primes which are averages of both their immediate and their second neighbors.at n=1A051795
• Primes p such that p-12, p and p+12 are consecutive primes.at n=25A053072
• a(1) = 2, a(n+1) is smallest prime factor of (2 * Product_{k=1..n} a(k)) + 1.at n=5A077073
• Prime numbers occurring at integer Pythagorean distance (radius) from 1 in Ulam square prime-spiral. Primes on axes are excluded.at n=36A078765
• Duplicate of A051795.at n=1A081416
• Primes p such that the smallest integer whose sum of decimal digits is p is prime.at n=26A129990
• Primes p such that continued fraction of (1 + sqrt(p))/2 has period 15: primes in A146338.at n=35A146360
• Greater of two consecutive primes, p < q, such that both p*q+p-q and p*q-p+q are prime numbers.at n=32A154552
• a(1)=2, a(2)=2, a(n)=a(n-2)+floor(a(n-2)*a(n-1)/(a(n-2)+a(n-1))).at n=45A173091
• Primes p such that (p+18), (p+36) and (p+72) are also prime.at n=28A175158
• Diagonal sums of number triangle A186826.at n=8A186828
• Number of nX4 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 3,0,1,1,1 for x=0,1,2,3,4.at n=4A197405
• Number of nX5 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 3,0,1,1,1 for x=0,1,2,3,4.at n=3A197406
• T(n,k)=Number of nXk 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 3,0,1,1,1 for x=0,1,2,3,4.at n=31A197409
• T(n,k)=Number of nXk 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 3,0,1,1,1 for x=0,1,2,3,4.at n=32A197409
• Least prime p such that the polynomial x^n - x^(n-1) - ... - 1 (mod p) has n distinct zeros.at n=5A211671
• Primes p of the form 420k + 1 for some k.at n=24A217587
• Primes of form p*q + 30, where p and q are consecutive primes.at n=14A229570