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%I #36 Jul 19 2023 12:15:32
%S 144,169,441,961,1089,9801,10404,10609,12544,12769,14884,40401,44521,
%T 48841,90601,96721,1004004,1006009,1022121,1024144,1026169,1042441,
%U 1044484,1062961,1212201,1214404,1216609,1236544,1238769,1256641
%N Non-palindromic squares which when written backwards remain square (and still have the same number of digits).
%C Squares with trailing zeros not included.
%C Sequence is infinite, since it includes, e.g., 10^(2k) + 4*10^k + 4 for all k. - _Robert Israel_, Sep 20 2015
%H Robert Israel, <a href="/A035090/b035090.txt">Table of n, a(n) for n = 1..798</a>
%H P. De Geest, <a href="http://www.worldofnumbers.com/square.htm">Palindromic Squares</a>
%H <a href="/index/Sq#sqrev">Index entry for sequences related to reversing digits of squares</a>
%F a(n) = A035123(n)^2. - _R. J. Mathar_, Jan 25 2017
%p rev:= proc(n) local L,i;
%p L:= convert(n,base,10);
%p add(L[-i]*10^(i-1),i=1..nops(L))
%p end proc:
%p filter:= proc(n) local t;
%p if n mod 10 = 0 then return false fi;
%p t:= rev(n);
%p t <> n and issqr(t)
%p end proc:
%p select(filter, [seq(n^2, n=1..10^5)]); # _Robert Israel_, Sep 20 2015
%t Select[Range[1200]^2,!PalindromeQ[#]&&IntegerLength[#]==IntegerLength[ IntegerReverse[ #]] && IntegerQ[Sqrt[IntegerReverse[#]]]&] (* _Harvey P. Dale_, Jul 19 2023 *)
%Y Reversing a polytopal number gives a polytopal number:
%Y cube to cube: A035123, A035124, A035125, A002781;
%Y square to square: A161902, A035090, A033294, A106323, A106324, A002779;
%Y square to triangular: A181412, A066702;
%Y tetrahedral to tetrahedral: A006030;
%Y triangular to square: A066703, A179889;
%Y triangular to triangular: A066528, A069673, A003098, A066569.
%Y Cf. A319388.
%K nonn,base
%O 1,1
%A _Patrick De Geest_, Nov 15 1998
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