OFFSET
0,4
FORMULA
a(n) = 2^n - A364671(n). - Andrew Howroyd, Jan 27 2024
EXAMPLE
The a(0) = 0 through a(5) = 18 subsets:
. . . {1,3} {1,3} {1,3}
{2,3} {1,4} {1,4}
{2,3} {1,5}
{3,4} {2,3}
{1,3,4} {2,5}
{2,3,4} {3,4}
{3,5}
{4,5}
{1,2,5}
{1,3,4}
{1,3,5}
{1,4,5}
{2,3,4}
{2,3,5}
{2,4,5}
{3,4,5}
{1,3,4,5}
{2,3,4,5}
MATHEMATICA
Table[Length[Select[Subsets[Range[n]], !SubsetQ[#, Differences[#]]&]], {n, 0, 10}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Aug 05 2023
EXTENSIONS
a(21) onwards (using A364671) added by Andrew Howroyd, Jan 27 2024
STATUS
approved