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 A327481 #7 Sep 13 2019 17:05:11
%S A327481 1,1,1,1,3,1,1,3,3,1,1,3,7,3,1,1,3,9,9,3,1,1,3,9,19,9,3,1,1,3,9,25,25,
%T A327481 9,3,1,1,3,9,29,51,29,9,3,1,1,3,9,31,75,75,31,9,3,1,1,3,9,31,93,151,
%U A327481 93,31,9,3,1,1,3,9,31,105,235,235,105,31,9,3,1
%N A327481 Triangle read by rows where T(n,k) is the number of nonempty subsets of {1..n} with mean k.
%C A327481 All terms are odd.
%e A327481 Triangle begins:
%e A327481 1
%e A327481 1 1
%e A327481 1 3 1
%e A327481 1 3 3 1
%e A327481 1 3 7 3 1
%e A327481 1 3 9 9 3 1
%e A327481 1 3 9 19 9 3 1
%e A327481 1 3 9 25 25 9 3 1
%e A327481 1 3 9 29 51 29 9 3 1
%e A327481 1 3 9 31 75 75 31 9 3 1
%e A327481 1 3 9 31 93 151 93 31 9 3 1
%e A327481 1 3 9 31 105 235 235 105 31 9 3 1
%e A327481 The subsets counted in row n = 5:
%e A327481 {1} {2} {3} {4} {5}
%e A327481 {1,3} {1,5} {3,5}
%e A327481 {1,2,3} {2,4} {3,4,5}
%e A327481 {1,3,5}
%e A327481 {2,3,4}
%e A327481 {1,2,4,5}
%e A327481 {1,2,3,4,5}
%t A327481 Table[Length[Select[Subsets[Range[n]],Mean[#]==k&]],{n,10},{k,n}]
%Y A327481 Row sums are A051293.
%Y A327481 The sequence of rows converges to A066571.
%Y A327481 The version for partitions is A327482.
%Y A327481 Cf. A000016, A063776, A065795, A135342, A327474, A327475, A327483, A327484.
%K A327481 nonn,tabl
%O A327481 1,5
%A A327481 _Gus Wiseman_, Sep 13 2019