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%I #8 Jan 17 2014 15:59:13
%S 18,81,1188,1818,1881,8118,8181,8811,111888,118188,118818,118881,
%T 181188,181818,181881,188118,188181,188811,811188,811818,811881,
%U 818118,818181,818811,881118,881181,881811,888111
%N List of words over {1,8} with equal numbers of 1's and 8's.
%C This is to 8 as A214530 is to 7, as A214530 is to 6, as A214522 is to 5, as A214521 is to 4, as A214488 is to 3, and as A214218 is to 2. All of these, interpreted as decimal integers are divisible by 9, because each pair of "1" and "8" contributes a digital sum of 9, hence the total is divisible by 9.
%H Harvey P. Dale, <a href="/A214531/b214531.txt">Table of n, a(n) for n = 1..1000</a>
%t With[{tb=Table[Join[PadRight[{},n,1],PadRight[{},n,8]],{n,3}]},FromDigits/@ Flatten[Permutations/@tb,1]] (* _Harvey P. Dale_, Jan 17 2014 *)
%Y Cf. A214218, A214488, A214521, A214522, A214524, A214530.
%K nonn,base,easy
%O 1,1
%A _Jonathan Vos Post_, Jul 20 2012