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Numbers whose squares have at least one 1 and one 2 in ternary representation.
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%I #7 May 07 2015 16:37:50

%S 4,5,7,8,10,12,13,14,15,17,20,21,22,23,24,25,26,28,30,31,32,34,35,36,

%T 37,38,39,40,41,42,43,44,45,46,47,49,50,51,52,53,56,58,59,60,61,62,63,

%U 64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,82,84

%N Numbers whose squares have at least one 1 and one 2 in ternary representation.

%C So a(n)^2 belongs to A125293.

%C Complement of A176189.

%H K. Mahler, <a href="http://matwbn.icm.edu.pl/ksiazki/aa/aa53/aa5316.pdf">The representation of squares to the base 3</a>, Acta Arith. Vol. 53, Issue 1 (1989), p. 99-106.

%t Select[Range[100],DigitCount[#^2,3,1]>0&&DigitCount[#^2,3,2]>0&] (* _Harvey P. Dale_, May 07 2015 *)

%Y Cf. A125293, A176189.

%K nonn,base

%O 1,1

%A _Michel Marcus_, Nov 12 2012