a(n) = Sum_{d|n} phi(d)^(n+d+1).A342618a(n) = Sum_{d|n} phi(d)^(n+d+1).Terms a(0) =1a(1) =2a(2) =129a(3) =514a(4) =4194305a(5) =9218a(6) =470184984577a(7) =17179877378External referencesoeis: A342618