65521

Properties

Appears in sequences

• Largest prime <= 2^n.at n=15A014234
• Arrange digits of cubes in descending order.at n=25A032554
• Numerators of continued fraction convergents to sqrt(910).at n=3A042758
• a(n) = Fibonacci(n) OR Fibonacci(n+1).at n=23A051123
• a(n) = 1 + Product_{k=1..n} Fibonacci(k).at n=7A052449
• Primes of the form A003266(n) + 1.at n=7A053413
• a(n) = the least positive integer k such that Omega(n+k) = Omega(k)+n, where Omega(m) (A001222) denotes the number of prime factors of m, counting multiplicity.at n=14A076158
• a(n) = 3*a(n-1) - a(n-2) - 3*a(n-3) + 2*a(n-4).at n=15A084173
• Numbers k such that the root-mean-square value of 1, 2, ..., k, i.e., sqrt((1/k)*Sum_{j=1..k} j^2), is an integer.at n=2A084231
• Primes of the form 2*p^2 - 1, where p is prime.at n=16A092057
• a(n) = 2^(n+1) - n.at n=14A095768
• Initial terms of chains consisting of four consecutive integers, for none of which is the value of sigma-function divisible by six.at n=9A097020
• a(n) = 2^(2*n)-(2*n-1).at n=8A100102
• Let j be the smallest integer for which 1+(1+1*n)+(1+2*n)+...+(1+j*n)=k^2=s. Then a(n)=1+j*n; if no such j exists, then a(n)=0.at n=38A100253
• Primes of the form 2^k - k + 1.at n=5A100362
• Largest prime <= 4^n.at n=7A104089
• a(n,m) =Floor[N[(-2 + Sqrt[3])^n + (-2 - Sqrt[3])^n]/2^m].at n=47A117809
• Define F(n) = 2^(2^n)+1 = n-th Fermat number, M(n) = 2^n-1 = the n-th Mersenne number. Then a(n) = F(n)-M(n)-1 = 2^(2^n) - 2^n + 1.at n=4A119564
• Largest prime factor of the odd Catalan number A038003(n).at n=13A120274
• Row sums of triangle A132044.at n=16A132045