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Perfect powers whose digit reversal is prime.
1

%I #12 Sep 22 2024 17:58:17

%S 16,32,125,128,196,361,784,1024,1369,1444,1600,1681,3844,7225,7921,

%T 9025,9409,11236,14161,18496,19321,19600,36100,37249,38416,70756,

%U 73441,75076,76729,78400,78961,97969,99856,102400,105625,107584,109561,111556

%N Perfect powers whose digit reversal is prime.

%C Conjectures: (1) Sequence is infinite. (2) For every n there are infinitely many members of the form k^n.

%H Harvey P. Dale, <a href="/A088112/b088112.txt">Table of n, a(n) for n = 1..471</a> (no further terms through 32 million)

%t Select[Range[120000],GCD@@FactorInteger[#][[All,2]]>1 && PrimeQ[ IntegerReverse[ #]]&] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, May 03 2018 *)

%Y Intersection of A001597 and A095179.

%K base,nonn

%O 1,1

%A _Amarnath Murthy_, Sep 25 2003

%E Corrected and extended by _Ray Chandler_, Oct 14 2003

%E Offset changed by _Andrew Howroyd_, Sep 22 2024