A325869 Number of maximal subsets of {1..n} containing n such that every pair of distinct elements has a different quotient.
1, 1, 1, 2, 3, 4, 6, 6, 6, 20, 32, 29, 57, 83, 113, 183, 373, 233, 549, 360
Offset: 1
Examples
The a(1) = 1 through a(7) = 6 subsets: {1} {1,2} {1,2,3} {1,3,4} {1,2,3,5} {1,2,5,6} {1,2,3,5,7} {2,3,4} {1,3,4,5} {2,3,5,6} {1,2,5,6,7} {2,3,4,5} {2,4,5,6} {2,3,4,5,7} {1,3,4,5,6} {2,3,5,6,7} {2,4,5,6,7} {1,3,4,5,6,7}
Crossrefs
Programs
-
Mathematica
fasmax[y_]:=Complement[y,Union@@(Most[Subsets[#]]&)/@y]; Table[Length[fasmax[Select[Subsets[Range[n]],MemberQ[#,n]&&UnsameQ@@Divide@@@Subsets[#,{2}]&]]],{n,10}]