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A036948 Smallest n-digit prime containing only the digits 6 and 7, or 0 if no such prime exists. 1

%I #15 Mar 09 2020 10:26:18

%S 7,67,677,0,67777,666667,6676667,66666667,666666667,6666666767,

%T 66666666667,666666676667,6666666667777,66666667677767,

%U 666666666667777,6666666666767777,66666666666667667,666666666666676667

%N Smallest n-digit prime containing only the digits 6 and 7, or 0 if no such prime exists.

%H Jinyuan Wang, <a href="/A036948/b036948.txt">Table of n, a(n) for n = 1..500</a>

%t Table[SelectFirst[10#+7&/@FromDigits/@Tuples[{6,7},n],PrimeQ],{n,0,17}]/. (Missing["NotFound"]->0) (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Apr 08 2019 *)

%Y Cf. A020469, A036229, A036322.

%K nonn,base

%O 1,1

%A _Patrick De Geest_, Jan 04 1999

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