C(15,8,2) <=6

Method of construction: lex covering

 1  2  3  4  5  6  7  8
 1  9 10 11 12 13 14 15
 2  3  4  5  9 10 11 12
 2  3  4  5  6 13 14 15
 6  7  8  9 10 11 12 13
 1  2  3  4  7  8 14 15