1,2

See A095029.

Dan Gordon, List of Cyclic Difference Sets.

Using the numbers {1 3 4 5 9}, every number in the range 1..10 can be written as a difference modulo 11 in two different ways:

1=4-3=5-4, 2=3-1=5-3, 3=4-1=(1-9) mod 11, 4=5-1=9-5, 5=9-4=(3-9) mod 11,

6=9-2=(4-9) mod 11, 7=(1-5) mod 11=(5-9) mod 11, 8=9-1=(1-4) mod 11,

9=(1-3) mod 11=(3-5) mod 11, 10=(3-4) mod 11=(4-5) mod 11.

Cf. A095025 number of cyclic difference sets with n elements, A095029 .. A095047 more examples of cyclic difference set with k=5..53.

Sequence in context: A049931 A058983 A010375 this_sequence A011246 A020863 A122401

Adjacent sequences: A095025 A095026 A095027 this_sequence A095029 A095030 A095031

fini,full,nonn

Hugo Pfoertner (hugo(AT)pfoertner.org), Jun 02 2004