A322472 Primes that are not base-9 deletable primes (written in base 10).

13, 17, 37, 73, 89, 97, 109, 113, 127, 131, 139, 149, 151, 157, 197, 227, 251, 257, 271, 277, 293, 307, 311, 313, 337, 359, 379, 397, 409, 419, 421, 433, 439, 457, 463, 487, 499, 503, 521, 523, 541, 569, 577, 587, 599, 601, 613, 617, 619, 631, 653, 661, 683, 733, 739, 743, 757, 761

Offset

1,1

Comments

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.

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 A322471.

Links

Robert Price, Table of n, a(n) for n = 1..889

Mathematica

b = 9; d = {};
p = Select[Range[2, 10000], PrimeQ[#] &];
For[i = 1, i <= Length[p], i++,
c = IntegerDigits[p[[i]], b];
If[Length[c] == 1, AppendTo[d, p[[i]]]; Continue[]];
For[j = 1, j <= Length[c], j++,
t = Delete[c, j];
If[t[[1]] == 0, Continue[]];
If[MemberQ[d, FromDigits[t, b]], AppendTo[d, p[[i]]]; Break[]]]]; Complement[Table[Prime[n], {n, PrimePi[Last[d]]}], d] (* Robert Price, Dec 09 2018 *)

Crossrefs

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

Sequence in context: A340053 A174056 A307894 * A166681 A109308 A263241

Adjacent sequences: A322469 A322470 A322471 * A322473 A322474 A322475

Keyword

nonn,base,easy

Author

Robert Price, Dec 09 2018

Status

approved