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%I #19 Dec 13 2015 01:10:26
%S 2,3,5,7,11,13,17,31,37,41,43,53,61,71,73,79,83,97,113,131,149,157,
%T 163,167,179,181,191,197,199,211,241,251,281,311,313,331,337,347,359,
%U 373,389,419,421,431,433,443,461,463,491,521,541,563,571,593,613,617,631,641,643,653
%N Down-sortable primes: Primes that are also primes after digits are sorted into decreasing order.
%C All 1- and 2-digit reversible primes (A007500) are trivially in this sequence. No primes from A056709 are in this sequence. Clearly all absolute primes (A003459) are sortable primes but not all sortable primes are absolute primes. - _Alonso del Arte_, Oct 08 2013
%H Francis J. McDonnell, <a href="/A211655/b211655.txt">Table of n, a(n) for n = 1..10000</a>
%H Francis J. McDonnell, <a href="/A211655/a211655.java.txt">Java Program</a>
%e 131 is prime and after sorting its digits into nonincreasing order we obtain 311, which is prime.
%e 163 is in the sequence because its digits sorted in decreasing order give 631, which is prime. (Note that this is not a reversible prime, since 361 = 19^2.)
%t Select[Prime[Range[200]], PrimeQ[FromDigits[-Sort[-IntegerDigits[#]]]] &] (* _T. D. Noe_, Apr 17 2012 *)
%Y Cf. A004186, A211654, A028864, A028867.
%K nonn,base,easy
%O 1,1
%A _Francis J. McDonnell_, Apr 17 2012
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