Sum_{d|n} 2^(d^2) * n^2/d^2.A262009Sum_{d|n} 2^(d^2) * n^2/d^2.Terms a(0) =2a(1) =24a(2) =530a(3) =65632a(4) =33554482a(5) =68719479000External referencesoeis: A262009