C(15,14,2) <=3

Method of construction: lex covering

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