27409

Properties

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has period 89.at n=27A020428
• Number of (w,x,y,z) with all terms in {1,...,n} and w^3>x^3+y^3+z^3.at n=20A212099
• a(n) = prime(n*prime(n)).at n=27A228529
• 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=38A232237
• a(1) = 2; thereafter, a(n) is the smallest prime not yet used which is compatible with the condition that a(n) is a non-quadratic residue modulo a(k) for the next n indices k = n + 1, n + 2, ..., 2n.at n=21A249797
• The Hwang-Deutsch function f_4(n).at n=49A260997
• Numbers n such that A003146(n) = floor(alpha^3*n)+1, where alpha = 1.839... is the positive real zero of x^3-x^2-x-1.at n=28A278353
• Primes p such that A001175(p) = (p-1)/6.at n=33A308791
• Number T(n,k) of endofunctions on [n] with exactly k cycles of length larger than 1; triangle T(n,k), n>=0, 0<=k<=floor(n/2), read by rows.at n=13A350446
• Primes p such that if q is the next prime, p+A004086(q) and q+A004086(p) are prime.at n=37A351728
• Prime numbersat n=2996