A325864 Number of subsets of {1..n} of which every subset has a different sum.

1, 2, 4, 7, 13, 22, 36, 56, 91, 135, 211, 307, 446, 625, 882, 1194, 1677, 2238, 3031, 4001, 5460, 6995, 9302, 11921, 15424, 19554, 25032, 31005, 39170, 48251, 59917, 73093, 90831, 109271, 134049, 160922, 196109, 234179, 284157, 335933, 408390, 482597, 575109

Offset

0,2

Links

Fausto A. C. Cariboni, Table of n, a(n) for n = 0..150 (terms 0..60 from Giovanni Resta)

Example

The a(0) = 1 through a(4) = 13 subsets:
  {}  {}   {}     {}     {}
      {1}  {1}    {1}    {1}
           {2}    {2}    {2}
           {1,2}  {3}    {3}
                  {1,2}  {4}
                  {1,3}  {1,2}
                  {2,3}  {1,3}
                         {1,4}
                         {2,3}
                         {2,4}
                         {3,4}
                         {1,2,4}
                         {2,3,4}

Mathematica

Table[Length[Select[Subsets[Range[n]], UnsameQ@@Plus@@@Subsets[#]&]], {n, 0, 10}]

Crossrefs

Cf. A002033, A108917, A143823, A196723, A275972.

Cf. A325860, A325865, A325866, A325867, A325877, A325878, A325879, A325880.

Sequence in context: A061257 A061255 A088111 * A143823 A119983 A364465

Adjacent sequences: A325861 A325862 A325863 * A325865 A325866 A325867

Keyword

nonn

Author

Gus Wiseman, Jun 01 2019

Extensions

a(18)-a(42) from Alois P. Heinz, Jun 03 2019

Status

approved