%I #8 Dec 21 2015 10:01:03
%S 1,4,9,121,484,676,2178,8712,10000,10201,12321,14641,40000,40804,
%T 44944,69696,90000,94249,698896,1002001,1210000,1234321,4008004,
%U 4840000,5221225,6760000,6948496,21780000,87120000,100000000,100020001
%N Numbers n such that n multiplied by its reverse yields a fourth power.
%C This sequence contains palindromic squares and palindromic squares with trailing zeros. Are 2178 and 8721 the only non-palindromic reversible pair in this sequence without trailing zeros?
%H Chai Wah Wu, <a href="/A131760/b131760.txt">Table of n, a(n) for n = 1..108</a>
%e 2178 = 2*9*121 and 8712 = 8*9*121, 2718*8712 = (2*3*11)^4.
%t Select[Range[1000000], IntegerQ[(#*FromDigits[Reverse[IntegerDigits[ # ]]])^(1/4)] &]
%Y Cf. A002779 = Palindromic squares.
%K nonn,base
%O 1,2
%A _Tanya Khovanova_, Sep 17 2007
%E a(20)-a(31) from _Donovan Johnson_, Oct 27 2008