OFFSET
0,1
LINKS
R. Zumkeller, Table of n, a(n) for n = 0..10000
EXAMPLE
a(25) = #{25=5^2, 225=15^2, 256=16^2, 625=25^2} = 4;
a(26) = #{256=16^2} = 1;
a(27) = #{} = 0;
a(28) = #{289=17^2} = 1;
a(29) = #{289=17^2, 529=23^2, 729=27^2} = 3.
MATHEMATICA
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 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Reinhard Zumkeller, Mar 01 2009
STATUS
approved