a(n) = (24^n - 1)/23.A218727a(n) = (24^n - 1)/23.Terms a(0) =0a(1) =1a(2) =25a(3) =601a(4) =14425a(5) =346201a(6) =8308825a(7) =199411801a(8) =4785883225a(9) =114861197401External referencesoeis: A218727