

A322443


Base8 deletable primes (written in base 10).


2



2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 83, 89, 101, 107, 109, 131, 137, 139, 151, 157, 163, 167, 179, 181, 191, 197, 199, 211, 223, 229, 233, 239, 251, 269, 277, 293, 317, 331, 337, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 401, 421, 431, 443, 461, 467, 479, 491
(list;
graph;
refs;
listen;
history;
text;
internal format)



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.
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..566


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[]]]];
d (* Robert Price, Dec 08 2018 *)


CROSSREFS

Cf. A080608, A080603, A096235A096246.
Sequence in context: A233360 A234960 A118850 * A219697 A078668 A038614
Adjacent sequences: A322440 A322441 A322442 * A322444 A322445 A322446


KEYWORD

nonn,base,easy


AUTHOR

Robert Price, Dec 08 2018


STATUS

approved



