This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A211655 #19 Dec 13 2015 01:10:26 %S A211655 2,3,5,7,11,13,17,31,37,41,43,53,61,71,73,79,83,97,113,131,149,157, %T A211655 163,167,179,181,191,197,199,211,241,251,281,311,313,331,337,347,359, %U A211655 373,389,419,421,431,433,443,461,463,491,521,541,563,571,593,613,617,631,641,643,653 %N A211655 Down-sortable primes: Primes that are also primes after digits are sorted into decreasing order. %C A211655 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 A211655 Francis J. McDonnell, <a href="/A211655/b211655.txt">Table of n, a(n) for n = 1..10000</a> %H A211655 Francis J. McDonnell, <a href="/A211655/a211655.java.txt">Java Program</a> %e A211655 131 is prime and after sorting its digits into nonincreasing order we obtain 311, which is prime. %e A211655 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 A211655 Select[Prime[Range[200]], PrimeQ[FromDigits[-Sort[-IntegerDigits[#]]]] &] (* _T. D. Noe_, Apr 17 2012 *) %Y A211655 Cf. A004186, A211654, A028864, A028867. %K A211655 nonn,base,easy %O A211655 1,1 %A A211655 _Francis J. McDonnell_, Apr 17 2012