{1}
{3}
{4}
{7}
{8}
{9}
{1, 8}
{1, 9}
{3, 4}
{3, 7}
{3, 8}
{3, 9}
{4, 7}
{4, 8}
{4, 9}
{7, 9}
{3, 4, 7}
{3, 4, 8}
{3, 4, 9}
{3, 7, 9}
{4, 7, 9}
{3, 4, 7, 9}
Created with the Wolfram Language