The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A325861 Number of maximal subsets of {1..n} such that every pair of distinct elements has a different quotient. 15
 1, 1, 1, 1, 3, 3, 6, 6, 9, 13, 32, 32, 57, 57, 140, 229, 373, 373, 549, 549, 825 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,5 LINKS EXAMPLE The a(1) = 1 through a(9) = 13 subsets:   {1}  {12}  {123}  {123}  {1235}  {1235}   {12357}   {23457}   {24567}                     {134}  {1345}  {1256}   {12567}   {24567}   {123578}                     {234}  {2345}  {2345}   {23457}   {123578}  {134567}                                    {2356}   {23567}   {125678}  {134578}                                    {2456}   {24567}   {134567}  {135678}                                    {13456}  {134567}  {134578}  {145678}                                                       {135678}  {145789}                                                       {145678}  {234579}                                                       {235678}  {235678}                                                                 {235789}                                                                 {345789}                                                                 {356789}                                                                 {1256789} MATHEMATICA fasmax[y_]:=Complement[y, Union@@(Most[Subsets[#]]&/@y)]; Table[Length[fasmax[Select[Subsets[Range[n]], UnsameQ@@Divide@@@Subsets[#, {2}]&]]], {n, 0, 10}] CROSSREFS The subset case is A325860. The maximal case is A325861. The integer partition case is A325853. The strict integer partition case is A325854. Heinz numbers of the counterexamples are given by A325994. Cf. A002033, A103300, A143823, A196724, A325859, A325868, A325869. Sequence in context: A168237 A290966 A049318 * A079551 A182843 A008805 Adjacent sequences:  A325858 A325859 A325860 * A325862 A325863 A325864 KEYWORD nonn,more AUTHOR Gus Wiseman, May 31 2019 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified June 1 13:20 EDT 2020. Contains 334762 sequences. (Running on oeis4.)