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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A157464 Number of distinct squares when inserting at most one digit in decimal representation of n.

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%I A157464 #5 Sep 12 2021 19:30:36
%S A157464 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 A157464 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 A157464 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 A157464 Number of distinct squares when inserting at most one digit in decimal representation of n.
%C A157464 a(A157465(n)) > 0; a(A000290(n)) > 0.
%H A157464 R. Zumkeller, <a href="/A157464/b157464.txt">Table of n, a(n) for n = 0..10000</a>
%e A157464 a(25) = #{25=5^2, 225=15^2, 256=16^2, 625=25^2} = 4;
%e A157464 a(26) = #{256=16^2} = 1;
%e A157464 a(27) = #{} = 0;
%e A157464 a(28) = #{289=17^2} = 1;
%e A157464 a(29) = #{289=17^2, 529=23^2, 729=27^2} = 3.
%t A157464 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 A157464 A157466.
%K A157464 base,nonn
%O A157464 0,1
%A A157464 _Reinhard Zumkeller_, Mar 01 2009