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A321657 Base-4 deletable primes (written in base 10).

%I A321657 #16 Dec 07 2018 11:53:56
%S A321657 2,3,7,11,13,19,23,29,31,43,47,53,59,61,67,71,79,83,103,107,109,113,
%T A321657 127,139,151,157,163,167,173,179,181,191,197,211,223,227,229,239,241,
%U A321657 251,263,269,271,283,307,311,317,331,359,383,397,419,431,433,439,443
%N A321657 Base-4 deletable primes (written in base 10).
%C A321657 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 A321657 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 A321657 Robert Price, <a href="/A321657/b321657.txt">Table of n, a(n) for n = 1..2796</a>
%t A321657 b = 4; d = {};
%t A321657 p = Select[Range[2, 10000], PrimeQ[#] &];
%t A321657 For[i = 1, i <= Length[p], i++,
%t A321657   c = IntegerDigits[p[[i]], b];
%t A321657   If[Length[c] == 1, AppendTo[d, p[[i]]]; Continue[]];
%t A321657   For[j = 1, j <= Length[c], j++,
%t A321657    t = Delete[c, j];
%t A321657    If[t[[1]] == 0, Continue[]];
%t A321657    If[MemberQ[d, FromDigits[t, b]], AppendTo[d, p[[i]]]; Break[]]]];
%t A321657 d (* _Robert Price_, Dec 06 2018 *)
%Y A321657 Cf. A080608, A080603, A096235-A096246.
%K A321657 nonn,base,easy
%O A321657 1,1
%A A321657 _Robert Price_, Nov 15 2018