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A322477 Base-12 deletable primes (written in base 10). 2
2, 3, 5, 7, 11, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 79, 83, 89, 101, 103, 107, 113, 127, 131, 137, 139, 149, 151, 163, 167, 173, 179, 181, 191, 197, 199, 211, 223, 227, 229, 233, 239, 251, 257, 263, 269, 271, 277, 281, 283, 293, 307, 311, 317, 331, 347, 349, 353, 359, 367, 373, 379 (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
MATHEMATICA
b = 12; 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 09 2018 *)
CROSSREFS
Sequence in context: A280409 A336370 A076805 * A074647 A108543 A042988
KEYWORD
nonn,base,easy
AUTHOR
Robert Price, Dec 09 2018
STATUS
approved

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Last modified April 25 16:45 EDT 2024. Contains 371989 sequences. (Running on oeis4.)