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%I A037069
%S A037069 83,881,8887,88883,888887,28888883,88888883,888888883,48888888883,
%T A037069 288888888889,888888888887,48888888888883,88888888888889,
%U A037069 888888888888883,18888888888888883,88888888888888889
%N A037069 Smallest prime containing exactly n 8's.
%t A037069 f[n_, b_] := Block[{k = 10^(n + 1), p = Permutations[ Join[ Table[b, 
               {i, 1, n}], {x}]], c = Complement[Table[j, {j, 0, 9}], {b}], q = 
               {}}, Do[q = Append[q, Replace[p, x -> c[[i]], 2]], {i, 1, 9}]; r 
               = Min[ Select[ FromDigits /@ Flatten[q, 1], PrimeQ[ # ] & ]]; If[r 
               ? Infinity, r, p = Permutations[ Join[ Table[ b, {i, 1, n}], {x, 
               y}]]; q = {}; Do[q = Append[q, Replace[p, {x -> c[[i]], y -> c[[j]]}, 
               2]], {i, 1, 9}, {j, 1, 9}]; Min[ Select[ FromDigits /@ Flatten[q, 
               1], PrimeQ[ # ] & ]]]]; Table[ f[n, 8], {n, 1, 18}]
%Y A037069 Cf. A065591, A037068, A034388, A036507-A036536.
%Y A037069 Cf. A037053, A037055, A037057, A037059, A037061, A037063, A037065, A037067, 
               A037071.
%Y A037069 Sequence in context: A112766 A128950 A068851 this_sequence A103233 A093283 
               A156924
%Y A037069 Adjacent sequences: A037066 A037067 A037068 this_sequence A037070 A037071 
               A037072
%K A037069 nonn,base,easy
%O A037069 1,1
%A A037069 Patrick De Geest (pdg(AT)worldofnumbers.com), Jan 04 1999.
%E A037069 Corrected by Jud McCranie (j.mccranie(AT)comcast.net), Jan 04 2001. More 
               terms from Erich Friedman (efriedma(AT)stetson.edu), Jun 03 2001.

    
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Last modified December 8 08:31 EST 2009. Contains 170430 sequences.


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