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%I #9 Aug 30 2016 18:29:15
%S 17,71,1177,1717,1771,7117,7171,7711,111777,117177,117717,117771,
%T 171177,171717,171771,177117,177171,177711,711177,711717,711771,
%U 717117,717171,717711,771117,771171,771711,777111
%N List of words over {1,7} with equal numbers of 1's and 7's.
%C This is to 7 as A214524 is to 6, as A214522 is to 5, as A214521 is to 4, as A214488 is to 3, and as A214218 is to 2. The subsequence of primes (when interpreted as decimal integers) is A087514.
%t Sort[FromDigits/@Flatten[Table[Permutations[PadRight[{},2n,{1,7}]],{n,3}],1]] (* _Harvey P. Dale_, Aug 30 2016 *)
%Y Cf. A214218, A214488, A214521, A214522, A214524.
%K nonn,base,easy
%O 1,1
%A _Jonathan Vos Post_, Jul 20 2012