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
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