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A322173 Base-6 deletable primes (written in base 10). 2
2, 3, 5, 11, 13, 17, 19, 23, 29, 31, 41, 47, 53, 59, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 227, 233, 239, 251, 257, 263, 269, 281, 283, 293, 311, 313, 317, 347, 353, 359, 373, 379, 383, 389, 397 (list; graph; refs; listen; history; text; internal format)
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.

LINKS

Robert Price, Table of n, a(n) for n = 1..3561

MATHEMATICA

b = 6; 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[]]]];

d (* Robert Price, Dec 06 2018 *)

CROSSREFS

Cf. A080608, A080603, A096235-A096246.

Sequence in context: A275059 A072538 A225856 * A216509 A075237 A040062

Adjacent sequences:  A322170 A322171 A322172 * A322174 A322175 A322176

KEYWORD

nonn,base,easy

AUTHOR

Robert Price, Nov 29 2018

STATUS

approved

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Last modified July 31 13:25 EDT 2021. Contains 346373 sequences. (Running on oeis4.)