A322444 Primes that are not base-8 deletable primes (written in base 10).

71, 73, 79, 97, 103, 113, 127, 149, 173, 193, 227, 241, 257, 263, 271, 281, 283, 307, 311, 313, 409, 419, 433, 439, 449, 457, 463, 487, 503, 521, 569, 577, 587, 593, 599, 607, 617, 631, 641, 647, 653, 661, 673, 701, 727, 733, 739, 743, 757, 769, 823, 827, 839, 881, 887, 907, 911, 919, 929

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 A322443 .

Links

Robert Price, Table of n, a(n) for n = 1..660

Mathematica

b = 8; 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 08 2018 *)

Crossrefs

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

Sequence in context: A104843 A322831 A127316 * A339700 A217414 A159025

Adjacent sequences: A322441 A322442 A322443 * A322445 A322446 A322447

Keyword

nonn,base,easy

Author

Robert Price, Dec 08 2018

Status

approved