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A321910 Base-7 deletable primes (written in base 10).

%I A321910 #42 Dec 06 2018 19:23:46
%S A321910 2,3,5,17,19,23,31,37,41,47,101,103,131,137,139,149,163,167,191,199,
%T A321910 223,227,233,241,251,263,293,311,313,317,331,691,709,719,727,733,787,
%U A321910 823,853,877,887,919,929,937,977,983,997,1013,1019,1021,1031,1049,1129,1171,1367,1399,1409,1511
%N A321910 Base-7 deletable primes (written in base 10).
%C A321910 A prime p is a base-b deletable prime if when written in base b it has the property that removing some digit leaves either the empty string or another deletable prime.
%C A321910 Deleting a digit cannot leave any leading zeros in the new string. For example, deleting the 2 in 2003 to obtain 003 is not allowed.
%H A321910 Robert Price, <a href="/A321910/b321910.txt">Table of n, a(n) for n = 1..808</a>
%t A321910 b = 7; d = {};
%t A321910 p = Select[Range[2, 10000], PrimeQ[#] &];
%t A321910 For[i = 1, i <= Length[p], i++,
%t A321910   c = IntegerDigits[p[[i]], b];
%t A321910   If[Length[c] == 1, AppendTo[d, p[[i]]]; Continue[]];
%t A321910   For[j = 1, j <= Length[c], j++,
%t A321910    t = Delete[c, j];
%t A321910    If[t[[1]] == 0, Continue[]];
%t A321910    If[MemberQ[d, FromDigits[t, b]], AppendTo[d, p[[i]]]; Break[]]]];
%t A321910 d (* _Robert Price_, Dec 06 2018 *)
%Y A321910 Cf. A080608, A080603, A096235-A096246.
%K A321910 nonn,base,easy
%O A321910 1,1
%A A321910 _Robert Price_, Nov 29 2018