116288

Appears in sequences

• a(n) = Sum_{j=1..n} c(j)^c(n+1-j) where c(k) is the k-th composite number.at n=2A196152
• G.f. satisfies: A(x) = 1 + x*A(x)*A(-x) + x^2*A(x)/A(-x).at n=20A209199
• Numbers x such that there exist three integers 0<x<=y<=z and t>0 such that sigma(x)^2 = sigma(y)^2 = sigma(z)^2 = x^2 + y^2 + z^2 + t^2.at n=39A385531