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.
%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