SOD 6.2: Second-order designs program
(c) 2010 Design Computing (designcomputing.net/)

Note: Best design for 4 factors in 81 runs.

try #     	73
seed      	1374620238
# of iterations	26
f         	0.00 (R)
det       	1.5738563E23
det*      	0.4345

Factor levels:

(1)	(2)	(3)	(4)	
-1	0	0	0	
-1	0	1	-1	
0	-1	-1	0	
1	-1	1	1	
0	-1	1	0	
0	1	-1	1	
-1	-1	1	1	
1	1	-1	1	
0	0	1	1	
1	1	1	0	
-1	1	1	-1	
1	-1	-1	0	
1	-1	1	-1	
-1	1	1	1	
0	1	-1	0	
1	1	-1	-1	
1	1	0	0	
-1	1	0	-1	
1	-1	1	1	
-1	1	-1	0	
1	1	0	1	
1	1	0	-1	
1	0	0	1	
1	-1	0	0	
1	-1	0	0	
0	1	1	-1	
0	-1	-1	-1	
-1	0	0	-1	
-1	-1	0	1	
0	0	-1	0	
0	1	1	-1	
0	1	0	-1	
-1	0	1	1	
1	0	0	-1	
-1	1	1	0	
-1	0	-1	1	
1	0	-1	0	
1	1	1	1	
0	0	0	-1	
0	-1	0	1	
1	-1	-1	-1	
0	-1	1	0	
-1	-1	-1	1	
0	0	-1	-1	
0	1	1	1	
-1	-1	-1	-1	
0	1	0	0	
-1	1	0	1	
1	-1	-1	1	
1	0	1	-1	
0	0	-1	-1	
-1	1	0	1	
-1	1	-1	-1	
-1	0	-1	-1	
-1	0	1	0	
0	-1	1	-1	
-1	-1	0	0	
1	0	-1	1	
0	0	0	0	
1	1	-1	-1	
0	-1	-1	1	
0	0	0	1	
-1	1	-1	0	
-1	-1	0	-1	
0	-1	0	-1	
1	1	1	0	
-1	-1	-1	0	
0	1	0	0	
-1	-1	1	-1	
1	0	0	1	
0	0	1	1	
0	1	-1	1	
0	0	1	0	
1	0	1	0	
1	-1	0	-1	
1	0	-1	0	
1	0	1	-1	
-1	0	-1	1	
-1	0	0	0	
-1	-1	1	0	
0	-1	0	1	

X'X

81	54	54	54	54	0	0	0	0	0	0	0	0	0	0	
	54	36	36	36	0	0	0	0	0	0	0	0	0	0	
		54	36	36	0	0	0	0	0	0	0	0	0	0	
			54	36	0	0	0	0	0	0	0	0	0	0	
				54	0	0	0	0	0	0	0	0	0	0	
					54	0	0	0	0	0	0	0	0	0	
						54	0	0	0	0	0	0	0	0	
							54	0	0	0	0	0	0	0	
								54	0	0	0	0	0	0	
									36	0	0	0	0	0	
										36	0	0	0	0	
											36	0	0	0	
												36	0	0	
													36	0	
														36	

inverse(X'X)

0.1111	-0.037	-0.037	-0.037	-0.037	0	0	0	0	0	0	0	0	0	-0	
	0.0556	0	0	0	0	0	0	0	0	0	0	0	0	-0	
		0.0556	0	0	0	0	0	0	0	0	0	0	0	-0	
			0.0556	0	0	0	0	0	0	0	0	0	0	-0	
				0.0556	0	0	0	0	0	0	0	0	0	-0	
					0.0185	0	0	0	0	0	0	0	0	-0	
						0.0185	0	0	0	0	0	0	0	-0	
							0.0185	0	0	0	0	0	0	-0	
								0.0185	0	0	0	0	0	-0	
									0.0278	0	0	0	0	-0	
										0.0278	0	0	0	-0	
											0.0278	0	0	-0	
												0.0278	0	-0	
													0.0278	-0	
														0.0278	

Note: SOD used 20.421 seconds.