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A052030 Primes base 10 that remain primes in four bases b, 2<=b<=10, expansions interpreted as decimal numbers. 3

%I #14 Mar 21 2015 01:58:46

%S 19,23,37,67,79,103,127,191,193,211,229,277,311,313,337,379,409,433,

%T 443,577,613,619,631,643,647,653,787,857,883,907,919,947,997,1021,

%U 1039,1087,1097,1123,1171,1279,1423,1429,1447,1459,1471,1567,1597,1669,1693

%N Primes base 10 that remain primes in four bases b, 2<=b<=10, expansions interpreted as decimal numbers.

%H Sebastian Petzelberger, <a href="/A052030/b052030.txt">Table of n, a(n) for n = 1..10000</a>

%H C. Rivera, <a href="http://www.primepuzzles.net/puzzles/puzz_024.htm">PP&P Puzzle 24: Primes in several bases</a>

%e 19 is 103_4, 31_6, 23_8 and 19_10.

%t Select[Prime[Range@ 265], Count[PrimeQ /@ Table[FromDigits[IntegerDigits[#, i]], {i, 2, 10}], True] == 4 &] (* _Michael De Vlieger_, Mar 20 2015 after _Harvey P. Dale_ at A052032 *)

%Y Cf. A038537, A052026-A052033.

%K nonn,base

%O 1,1

%A _Patrick De Geest_, Dec 15 1999

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Last modified April 18 14:46 EDT 2024. Contains 371780 sequences. (Running on oeis4.)