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A110811 Perfect powers not a multiple of 10 whose digit reversal is also a perfect power (not necessarily with the same exponent, but with exponent > 1). 2

%I #11 Jun 01 2018 18:38:38

%S 1,4,8,9,121,144,169,343,441,484,676,961,1089,1331,9801,10201,10404,

%T 10609,12321,12544,12769,14641,14884,40401,40804,44521,44944,48841,

%U 69696,90601,94249,96721,698896,1002001,1004004,1006009,1022121,1024144

%N Perfect powers not a multiple of 10 whose digit reversal is also a perfect power (not necessarily with the same exponent, but with exponent > 1).

%C All palindromic perfect powers are trivial members, but there are infinitely many nontrivial members.

%H Chai Wah Wu, <a href="/A110811/b110811.txt">Table of n, a(n) for n = 1..867</a>

%e 12^2 =144, digit reversal of 144 is 441= 21^2. 12769=113^2, reversal(12769) = 96721 = 311^2.

%t Join[{1},Select[Range[11 10^5],Mod[#,10]!=0&&GCD@@FactorInteger[#][[All,2]]>1&&GCD@@FactorInteger[IntegerReverse[#]][[All,2]]>1&]] (* _Harvey P. Dale_, Jun 01 2018 *)

%Y This is a subset of A115656 and also a subset of A001597. See also A118895 to include terms with trailing zeros.

%K base,easy,nonn

%O 1,2

%A _Amarnath Murthy_, Aug 15 2005

%E Corrected and extended by _Joshua Zucker_, May 04 2006

%E Description and offset edited by _Chai Wah Wu_, Jun 06 2016

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Last modified April 25 12:33 EDT 2024. Contains 371969 sequences. (Running on oeis4.)