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Squares which have one or more occurrences of exactly four different digits.
3

%I #17 May 03 2018 12:05:19

%S 1024,1089,1296,1369,1764,1849,1936,2304,2401,2601,2704,2809,2916,

%T 3025,3249,3481,3721,4096,4356,4761,5041,5184,5329,5476,6084,6241,

%U 6724,7056,7396,7569,7921,8649,9025,9216,9604,9801,10609,10816,11025,11236,12544,12996

%N Squares which have one or more occurrences of exactly four different digits.

%C The first term having a repeated digit is 10609.

%H Colin Barker, <a href="/A235719/b235719.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) = A054032(n)^2.

%e 5329 is in the sequence because 5329 = 73^2 and 5329 contains exactly four different digits: 2, 3, 5 and 9.

%t Select[Range[150]^2,Length[Union[IntegerDigits[#]]]==4&] (* _Harvey P. Dale_, May 03 2018 *)

%o (PARI) s=[]; for(n=1, 300, if(#vecsort(eval(Vec(Str(n^2))),,8)==4, s=concat(s, n^2))); s

%Y Cf. A235717, A235718, A235720-A235724, A225218.

%K nonn,base

%O 1,1

%A _Colin Barker_, Jan 15 2014