a(n) = ((2^n+1)^n + (2^n-1)^n)/2.A172341a(n) = ((2^n+1)^n + (2^n-1)^n)/2.Terms a(0) =2a(1) =17a(2) =536a(3) =67073a(4) =33882272a(5) =68971196417External referencesoeis: A172341