a(1) = 1, a(n+1) = Sum_{d|n} a(d)^2.A333120a(1) = 1, a(n+1) = Sum_{d|n} a(d)^2.Terms a(0) =1a(1) =1a(2) =2a(3) =5a(4) =27a(5) =730a(6) =532906a(7) =283988804837External referencesoeis: A333120