%I A048072
%S A048072 0,0,1,2,6,13,21,45,91,154,322,645,1125,2325,4651,8301,17061,34123,
%T A048072 61915,126763,253527,465746,950818,1901637,3527109,7184421,14368843,
%U A048072 26855641,54604081,109208163,205390163,416990563,833981127
%N A048072 Number of nonempty subsets of {1,2,...,n} in which exactly 1/3 of the 
               elements are <= (n+2)/3.
%Y A048072 Sequence in context: A082722 A030416 A006284 this_sequence A026052 A049616 
               A064960
%Y A048072 Adjacent sequences: A048069 A048070 A048071 this_sequence A048073 A048074 
               A048075
%K A048072 nonn
%O A048072 1,4
%A A048072 Clark Kimberling (ck6(AT)evansville.edu)