%I #5 Jun 21 2013 16:45:40
%S 10,49,162,220,170,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
%T 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
%U 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
%N Number of n-digit numbers x such that the digits of x^2 occur with frequency 1.
%C After a(5), all terms are 0.
%e All numbers 0 to 9 have squares containing only digits of frequency 1: 0, 1, 4, 9, 16, 25, 36, 49, 64, 81.
%t cnt = 0; x = 0; t2 = Table[While[x < 10^n, If[Union[Last[Transpose[Tally[IntegerDigits[x^2]]]]] == {1}, cnt++]; x++]; cnt, {n, 5}]; Differences[Join[{0}, t2]]
%Y Cf. A225428, A226796.
%K nonn,base
%O 1,1
%A _T. D. Noe_, Jun 21 2013