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%I #5 Sep 12 2021 19:30:36
%S 4,3,1,1,3,1,3,0,1,2,1,1,1,0,1,0,3,0,0,2,0,1,1,0,1,4,1,0,1,3,0,1,1,0,
%T 1,0,2,0,0,0,1,2,0,0,3,0,0,0,1,1,0,0,1,0,0,0,2,1,0,1,0,2,1,0,1,1,1,1,
%U 0,1,0,0,1,0,1,0,2,0,1,1,0,2,0,0,3,0,0,0,0,1,1,1,0,0,0,0,2,0,0,0,3,0,1,0,1
%N Number of distinct squares when inserting at most one digit in decimal representation of n.
%C a(A157465(n)) > 0; a(A000290(n)) > 0.
%H R. Zumkeller, <a href="/A157464/b157464.txt">Table of n, a(n) for n = 0..10000</a>
%e a(25) = #{25=5^2, 225=15^2, 256=16^2, 625=25^2} = 4;
%e a(26) = #{256=16^2} = 1;
%e a(27) = #{} = 0;
%e a(28) = #{289=17^2} = 1;
%e a(29) = #{289=17^2, 529=23^2, 729=27^2} = 3.
%t Join[{4},Table[Count[Union[Flatten[Table[FromDigits[Insert[IntegerDigits[n],d,m]],{d,0,9},{m,IntegerLength[n]+1}]]],_?(IntegerQ[Sqrt[#]]&)],{n,110}]] (* _Harvey P. Dale_, Sep 12 2021 *)
%Y A157466.
%K base,nonn
%O 0,1
%A _Reinhard Zumkeller_, Mar 01 2009