ibd 10.0: Program for Constructing Incomplete Block Designs
(c) 2018 Design Computing (http://designcomputing.net/)

Note: Best IBD for v=60, k=9, r=3 and b=20

Try	iter	E	E/U	Concurrences
18	55	0.879	1	0(1050) 1(720) 

Plan for try 18 using seed -47090275 (blocks are columns):

33	20	40	11	34	28	49	37	42	58	56	18	30	5	32	49	5	10	32	39	
36	54	44	56	43	17	55	50	53	17	58	6	7	0	3	21	13	19	46	1	
48	11	8	27	18	48	41	54	16	15	36	30	39	51	10	1	27	25	40	26	
14	43	36	34	31	9	57	45	9	8	38	51	50	35	53	22	28	6	59	42	
16	41	9	7	59	50	26	52	52	34	3	23	33	57	44	13	2	55	19	46	
37	4	47	45	21	23	38	55	0	14	21	29	57	45	28	7	39	20	17	15	
5	12	2	16	25	1	47	31	13	4	24	47	53	24	31	37	58	8	52	35	
26	22	43	23	0	25	59	15	41	29	30	12	40	10	14	51	18	56	24	12	
6	48	35	46	33	38	27	2	29	49	54	32	20	4	11	44	19	42	22	3	

Note: ibd used 0.256 seconds.
Note: Evaluation copy - purchase at www.designcomputing.net