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%I #12 Apr 18 2017 16:15:15
%S 16,25,36,49,64,81,100,121,144,225,400,441,484,676,900,1444,7744,
%T 10000,11881,29929,40000,44944,55225,69696,90000,1000000,4000000,
%U 9000000,9696996,100000000,400000000,900000000,6661661161,10000000000,40000000000,90000000000
%N Squares which have one or more occurrences of exactly two different digits.
%C The first term having a repeated digit is 100.
%C This sequence is the same as A018885, except that A018885 has four additional leading terms.
%F a(n) = A016069(n)^2.
%e 69696 is in the sequence because 69696 = 264^2 and 69696 contains exactly two different digits: 6 and 9.
%o (PARI) s=[]; for(n=1,10000, if(#vecsort(eval(Vec(Str(n^2))),,8)==2, s=concat(s, n^2))); s
%Y Cf. A235718-A235724, A225218.
%K nonn,base
%O 1,1
%A _Colin Barker_, Jan 15 2014