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A263242 Larger of emirp pairs that are merely reversals of their end digits. 3


%S 31,71,73,97,311,701,733,743,751,761,907,937,941,953,967,971,983,991,

%T 3221,9001,9221,9227,9551,9661,9883,32321,33931,34141,34841,35051,

%U 36061,36761,37571,39791,70001,71711,72221,73331,74143,74441,74843,74941,75253,76261,76463,76561

%N Larger of emirp pairs that are merely reversals of their end digits.

%C The first digit is always larger than the last digit.

%H Harvey P. Dale, <a href="/A263242/b263242.txt">Table of n, a(n) for n = 1..500</a>

%t epQ[n_]:=Module[{idn=IntegerDigits[n],mid},mid=Rest[Most[idn]];PrimeQ[ IntegerReverse[n]]&&mid==Reverse[mid]&&idn[[1]]>idn[[-1]]]; Select[ Prime[Range[6,8000]],epQ] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Oct 10 2016 *)

%Y Cf. A006567, A109309, A263240, A263241.

%K nonn,base

%O 1,1

%A _Lekraj Beedassy_, Oct 13 2015

%E Corrected by _Harvey P. Dale_, Oct 10 2016

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Last modified September 17 09:00 EDT 2021. Contains 347478 sequences. (Running on oeis4.)