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 A109073 #4 Mar 30 2012 17:26:17
%S A109073 0,0,1,1,2,1,1,2,2,2,0,1,2,2,2,2,2,3,3,2,1,2,3,2,3,1,1,1,2,3,1,2,3,4,
%T A109073 4,3,3,3,4,4,2,2,3,3,4,3,3,4,3,3,1,3,3,4,4,3,3,4,4,4,1,3,4,2,2,3,3,4,
%U A109073 3,3,2,3,4,3,2,2,1,4,3,4,2,3,3,2,4,3,3,3,4,3,2,3,4,3,4,2,2,2,3,3,0,1,2,2,2
%N A109073 Number of decimal digits ( counted with multiplicity ) in n^2 but not in n.
%C A109073 Cf. A076493 Number of common and distinct decimal digits of n and n^2, A109071 Number of common decimal digits ( counted with multiplicity ) of n and n^2, A109072 Number of decimal digits ( counted with multiplicity ) in n but not in n^2.
%e A109073 a(35)=4 because 34^2=1156 and there are 4 digits (counted with multiplicity) which are in 34^2 but not in 34.
%t A109073 UnsortedComplement[x_List, y__List]:=Replace[x, Dispatch[(#\[RuleDelayed]Sequence[])&/@Union[y]], 1]; Table[Length[UnsortedComplement[IntegerDigits[n], IntegerDigits[n^2]]], {n, 0, 200}]
%Y A109073 Cf. A076493, A109071, A109072.
%K A109073 base,easy,nonn
%O A109073 0,5
%A A109073 _Zak Seidov_, Jun 20 2005