%I #11 Jan 05 2018 13:01:07
%S 0,81,9729,996399,99954999,99630099630,999993699999,99999927999999,
%T 99999991899999991,9999999990999999999,999999999009999999990,
%U 99999999900099999999900,9999999990000999999999000,999999999000009999999990000,99999999999630099999999999630
%N a(n) is the largest number such that all of a(n)'s length-n substrings are distinct and divisible by 81.
%H Hans Havermann, <a href="/A093211/a093211.txt">Table of A093211-A093299</a>
%e a(4) is 996399 because its length-4 substrings (9963, 9639, 6399) are all distinct and divisible by 81 and there is no larger number with this property.
%Y Cf. A093211, A093212, ..., A093299.
%K base,nonn
%O 1,2
%A _Hans Havermann_, Mar 29 2004
%E a(11)-a(15) from _John Cerkan_, Jan 05 2018