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A235717 Squares which have one or more occurrences of exactly two different digits. 11

%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

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Last modified March 29 10:59 EDT 2024. Contains 371277 sequences. (Running on oeis4.)