a(0) = 1; a(n) = 4^(n+1)*a(n-1)+1.A130449a(0) = 1; a(n) = 4^(n+1)*a(n-1)+1.Terms a(0) =1a(1) =17a(2) =1089a(3) =278785a(4) =285475841External referencesoeis: A130449