20611

Properties

Appears in sequences

• Least prime in A031934 (lesser of 16-twins) whose distance to the next 16-twin is 6*n.at n=24A052357
• Prime numbers occurring at integer Pythagorean distance (radius) from 1 in Ulam square prime-spiral. Primes on axes are excluded.at n=30A078765
• Numbers k such that k, sigma(k) and phi(k) have the same decimal digits (ignoring multiplicity).at n=26A082059
• Primes which are also prime if their base 64 representation is interpreted as a base 10 number.at n=39A090717
• a(n) = (n^5 - 133*n^4 + 6729*n^3 - 158379*n^2 + 1720294*n - 6823316)/4.at n=15A121887
• Primes congruent to 54 mod 61.at n=38A142852
• Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 101-111-101 pattern in any orientation.at n=24A146434
• Primes that are the difference between a fourth power and a positive cube.at n=32A161735
• Primes p such that each of the numbers p^k for k=1..5 has exactly two 1s in its decimal representation.at n=2A175964
• a(1) = 1, a(n+1) = least prime p > a(n) such that a(n) + p is a square.at n=21A178825
• G.f.: A(x) = Sum_{n>=0} x^n / Product_{k=1..n} (1-x^k)^k.at n=21A206100
• a(n) = 111*n^2 - 3123*n + 10753.at n=31A211607
• a(n) = Sum_{k=0..n} binomial(n,k)^2*Lucas(k) where Lucas(n) = A000032(n).at n=7A219673
• Number of (n+1) X 6 0..1 matrices with each 2 X 2 subblock idempotent.at n=13A224547
• Primes of the form floor(Pi*k^2).at n=13A227794
• Sum of the numbers N*(n) and N**(n) in A242974.at n=4A243867
• Number of factorizations of m^n into 3 factors, where m is a product of exactly 3 distinct primes and each factor is a product of n primes (counted with multiplicity).at n=30A257464
• Prime numbers that have a triangular Voronoi cell in the Voronoi diagram of the Ulam prime spiral.at n=35A257527
• Primes of the form abs((1/4)*(n^5 - 133n^4 + 6729n^3 - 158379n^2 + 1720294n - 6823316)) in order of increasing nonnegative n.at n=15A272710
• T(n,k)=Number of nXk 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 0, 1 or 3 neighboring 1s.at n=46A297607