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!)
 A326156 Number of nonempty subsets of {1..n} whose product is divisible by their sum. 13
 0, 1, 2, 4, 5, 10, 19, 34, 64, 129, 267, 541, 1104, 2253, 4694, 9804, 18894, 38539, 76063, 155241, 311938, 636120, 1299869, 2653853, 5183363, 10272289, 20958448, 40945577, 81745769, 167048919, 329598054, 671038751, 1301431524, 2618590422, 5305742557, 10582105199, 20660489585, 42075929255, 85443680451, 172057673225, 338513788818 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Bert Dobbelaere, C++ program EXAMPLE The a(1) = 1 through a(6) = 19 subsets:   {1}  {1}  {1}      {1}      {1}          {1}        {2}  {2}      {2}      {2}          {2}             {3}      {3}      {3}          {3}             {1,2,3}  {4}      {4}          {4}                      {1,2,3}  {5}          {5}                               {1,2,3}      {6}                               {1,4,5}      {3,6}                               {2,3,5}      {1,2,3}                               {3,4,5}      {1,4,5}                               {1,2,3,4,5}  {2,3,5}                                            {2,4,6}                                            {3,4,5}                                            {4,5,6}                                            {1,2,3,6}                                            {1,3,5,6}                                            {3,4,5,6}                                            {1,2,3,4,5}                                            {1,2,3,4,6}                                            {2,3,4,5,6} MATHEMATICA Table[Length[Select[Subsets[Range[n], {1, n}], Divisible[Times@@#, Plus@@#]&]], {n, 0, 10}] CROSSREFS Cf. A053632, A057567, A057568, A059529, A063865, A301987, A326150, A326151, A326153/A326154, A326155, A326158, A326178, A326179, A326180. Sequence in context: A133040 A018424 A240100 * A000675 A005018 A249399 Adjacent sequences:  A326153 A326154 A326155 * A326157 A326158 A326159 KEYWORD nonn AUTHOR Gus Wiseman, Jun 11 2019 EXTENSIONS a(21)-a(30) from Alois P. Heinz, Jun 13 2019 a(31)-a(40) from Bert Dobbelaere, Jun 22 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 August 12 05:33 EDT 2020. Contains 336438 sequences. (Running on oeis4.)