a(1)=0, a(n) is the smallest nonprime > (n-1)^smallest digit of a(n-1).

Terms

a(0) =0a(1) =4a(2) =18a(3) =4a(4) =258a(5) =26a(6) =38a(7) =344a(8) =513a(9) =10a(10) =4a(11) =14642a(12) =14a(13) =14a(14) =15a(15) =16a(16) =18a(17) =18a(18) =20a(19) =4a(20) =160002a(21) =4a(22) =234257a(23) =530a(24) =4a(25) =390626a(26) =4a(27) =531442a(28) =30a(29) =4