19717

Properties

Appears in sequences

• Pisot sequence T(5,9), a(n) = floor(a(n-1)^2/a(n-2)).at n=15A020750
• Sum of n plus its prime factors associated with A020700.at n=26A020905
• Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 80 ones.at n=15A031848
• Primes which are not the sum of consecutive composite numbers.at n=40A037174
• Integers that can be expressed as the sum of consecutive primes in exactly 5 ways.at n=6A055000
• Numbers n such that n divides the (left) concatenation of all numbers <= n written in base 14 (most significant digit on right).at n=11A061967
• (1-2*cos(1/11*Pi))^n+(1+2*cos(2/11*Pi))^n+(1-2*cos(3/11*Pi))^n+(1+2*cos(4/11*Pi))^n+(1-2*cos(5/11*Pi))^n.at n=9A062883
• Primes expressible as the sum of (at least two) consecutive primes in at least 4 ways.at n=5A067380
• Primes p such that sigma(k) = phi(prime(k)-1), where p = prime(k).at n=15A107815
• Primes p such that p's set of distinct digits is {1,7,9}.at n=18A108384
• 1 together with terms of A037174.at n=41A140464
• Primes congruent to 11 mod 59.at n=37A142738
• Primes congruent to 14 mod 61.at n=34A142812
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, -1), (0, -1, 1), (0, 0, 1), (1, 1, 0)}.at n=8A150188
• Expansion of (5-16*x+6*x^2+10*x^3-2*x^4)/(1-4*x+2*x^2+5*x^3-2*x^4-x^5).at n=10A189235
• Primes that are sum of both three and five consecutive primes.at n=28A211170
• a(n) = 3^n + Fibonacci(n).at n=9A212262
• Primes such that concatenation of two adjacent terms and two adjacent digits is also prime.at n=37A224929
• Primes which are not the sum of two or more consecutive nonprime numbers.at n=38A257393
• a(n) is the least m > 1 such that (prime(n)#)^n - m is prime.at n=34A268608