%I A145675
%S A145675 1,3,73,12787,13698241
%N A145675 Number of n X n {0,-1,1}-matrices A such that permanent( |A| ) = | det 
               A |, where |A| is obtained from A by taking the absolute value of 
               each entry.
%C A145675 Also the number of n X n sign-nonsingular matrices (see reference for 
               definition).
%D A145675 Brualdi, Richard A. and Shader, Bryan L., On sign-nonsingular matrices 
               and the conversion of the permanent into the determinant, in Applied 
               Geometry and Discrete Mathematics (The Victor Klee Festschrift), 
               pp. 117-134, DIMACS Ser. Discrete Math. Theoret. Comput. Sci., 4, 
               Amer. Math. Soc., Providence, RI, 1991.
%Y A145675 Cf. A145676.
%Y A145675 Sequence in context: A020517 A119017 A002667 this_sequence A162601 A093183 
               A125520
%Y A145675 Adjacent sequences: A145672 A145673 A145674 this_sequence A145676 A145677 
               A145678
%K A145675 nonn
%O A145675 0,2
%A A145675 N. J. A. Sloane (njas(AT)research.att.com), Mar 26 2009
%E A145675 a(1)-a(4) computed by E. W. Weisstein (eric(AT)weisstein.com), Mar 26, 
               2009