504309

Appears in sequences

• a(n+1) = Sum_{k=0..floor(n/tau)} a(k) * a(n-k), where tau = (1+sqrt(5))/2.at n=19A030040
• Integers k such that there exists an integer 0<m<k such that sigma(m)^2 + sigma(k)^2 = 2*(m^2+k^2).at n=9A384255