153425

Appears in sequences

• Numbers n for which phi(n)=sigma(n'), where phi is the Euler totient function, sigma is the sum of divisors and n' the arithmetic derivative of n.at n=16A189057
• Numerator of H(n+4) - H(n), where H(n) = Sum_{k=1..n} 1/k.at n=40A189642
• a(n) = 4^(2*(n-1)^2) * Product_{1<=i,j<=n-1} (1 + sin(i*Pi/(2*n))^2 * sin(j*Pi/(2*n))^2).at n=2A340167