

A321596


Primes that are not base2 deletable primes (written in base 10).


1



17, 31, 41, 67, 71, 89, 97, 103, 113, 127, 131, 139, 181, 191, 193, 199, 223, 227, 233, 239, 241, 251, 257, 263, 269, 271, 283, 337, 353, 367, 373, 379, 383, 401, 409, 431, 433, 439, 443, 449, 463, 479, 487, 491, 499, 503, 509, 521, 523, 541, 547, 571, 577
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OFFSET

1,1


COMMENTS

A prime p is a baseb 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. However, in base 2 we adopt the convention that 2 = 10 and 3 = 11 are deletable.
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.
Complement of all primes and A096246.


LINKS

Robert Price, Table of n, a(n) for n = 1..2351


MATHEMATICA

d = {2, 3};
For[n = 3, n <= 15, n++,
p = Select[Range[2^(n  1), 2^n  1], PrimeQ[#] &];
For[i = 1, i <= Length[p], i++,
c = IntegerDigits[p[[i]], 2];
For[j = 1, j <= n, j++,
t = Delete[c, j];
If[t[[1]] == 0, Continue[]];
If[MemberQ[d, FromDigits[t, 2]], AppendTo[d, p[[i]]]; Break[]]]]]; Complement[Table[Prime[n], {n, PrimePi[Last[d]]}], d]


CROSSREFS

Cf. A080608, A080603, A096235A096246.
Sequence in context: A062579 A134076 A258029 * A160961 A260805 A267781
Adjacent sequences: A321593 A321594 A321595 * A321597 A321598 A321599


KEYWORD

nonn,base,easy


AUTHOR

Robert Price, Nov 14 2018


STATUS

approved



