a(n) = Sum_{d|n} d^(2*d).A308696a(n) = Sum_{d|n} d^(2*d).Terms a(0) =1a(1) =17a(2) =730a(3) =65553a(4) =9765626a(5) =2176783082a(6) =678223072850External referencesoeis: A308696