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Primes that are not base-5 deletable primes (written in base 10).
1

%I #11 Dec 06 2018 19:23:15

%S 5,29,31,41,43,83,101,109,127,131,139,149,151,157,163,167,173,179,181,

%T 191,193,199,211,223,229,233,241,251,257,277,281,283,293,313,331,349,

%U 383,401,409,419,421,431,433,443,457,461,463,467,491,499,509,521,541,577,587,593,599

%N Primes that are not base-5 deletable primes (written in base 10).

%C 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 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.

%C Complement of all primes and A321700.

%H Robert Price, <a href="/A321701/b321701.txt">Table of n, a(n) for n = 1..31550</a>

%t b = 5; d = {};

%t p = Select[Range[2, 10000], PrimeQ[#] &];

%t For[i = 1, i <= Length[p], i++,

%t c = IntegerDigits[p[[i]], b];

%t If[Length[c] == 1, AppendTo[d, p[[i]]]; Continue[]];

%t For[j = 1, j <= Length[c], j++,

%t t = Delete[c, j];

%t If[t[[1]] == 0, Continue[]];

%t If[MemberQ[d, FromDigits[t, b]], AppendTo[d, p[[i]]]; Break[]]]]; Complement[Table[Prime[n], {n, PrimePi[Last[d]]}], d] (* _Robert Price_, Dec 06 2018 *)

%Y Cf. A080608, A080603, A096235-A096246, A321657.

%K nonn,base,easy

%O 1,1

%A _Robert Price_, Nov 17 2018