cibd 10.0: Program for Constructing cyclic IBDs of size (v,k,r)
(c) 2018 Design Computing (http://designcomputing.net/)

Note: Best cyclic IBD for v=15, k=4, r=4, b=15

Try	iter	E	E/U	Concurrences
1	1	0.795	0.999	0(2) 1(12) 

Initial block(s) and the no. of blocks generated by each initial block for try 1 using seed 1533475903850:

0	14	4	12	 (15)

Plan (blocks are columns):

9	11	7	2	7	8	9	10	2	8	5	6	6	1	4	
5	14	10	10	12	11	12	3	7	4	13	11	9	6	0	
2	13	9	12	5	10	11	5	0	1	0	4	8	14	12	
4	3	14	13	8	0	1	6	3	3	1	7	13	2	14	

Note: cibd used 2.967 seconds.
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