27541

Properties

Appears in sequences

• Primes with 19 as smallest positive primitive root.at n=23A061331
• Number of ordered triples (a, b, c) with gcd(a, b, c) = 1 and 1 <= {a, b, c} <= n.at n=31A071778
• (1/8)*number of equilateral triangles that can be formed from the points of an (n+1)X(n+1)X(n+1) lattice cube.at n=11A103501
• Number of permutations of length n which avoid the patterns 2314, 3142, 4312.at n=9A116777
• Centered triangular numbers that are prime.at n=30A125602
• G.f.: A(x) = x/Series_Reversion(x*G(x)) where G(x) = Sum_{n>=0} n^n*x^n.at n=6A182957
• Number of nX3 0..4 arrays with each element equal to the number its horizontal and vertical neighbors equal to 2.at n=19A197056
• Primes p such that p-2 and q are primes, where q is concatenation of binary representations of p and p-2: q = p * 2^L + p-2, where L is the length of binary representation of p-2: L=A070939(p-2).at n=39A232237
• Number of partitions p of n such that the number of numbers having multiplicity 1 in p is a part and the number of numbers having multiplicity > 1 is a part.at n=43A241414
• a(n) = 21*n^2 - 33*n + 13.at n=36A289134
• Primes p such that p=prime(k), prime(k+1), and prime(k+2) end in the same digit.at n=27A328452
• Number of ordered triples (x, y, z) with gcd(x, y, z) = 1 and 1 <= {x, y, z} <= 2^n.at n=5A342935
• Lexicographically earliest sequence of numbers whose partial products are all Fermat pseudoprimes to base 2 (A001567).at n=8A374027
• Prime numbersat n=3009